These Chocolate Chunk Zucchini Oat Bars are the kind of easy, wholesome treat that disappears quickly. They’re soft and chewy with a hearty oat texture, plenty of fresh zucchini, warm cinnamon, and gooey pockets of melty chocolate in every bite. They’re sweet enough to feel like dessert, but wholesome enough to serve for breakfast, pack into lunchboxes, or enjoy as an afternoon snack.
If you have a garden overflowing with zucchini in the summer, this is one recipe you’ll want to keep handy. The zucchini adds moisture and tenderness without making the bars taste like it’s filled with vegetables, and the combination of old-fashioned oats and oat flour gives them a satisfying, chewy texture.
These zucchini oat bars are delicious warm from the oven, but they become even chewier once they’ve cooled completely. Serve them with coffee or tea for breakfast, tuck one into a lunchbox, or keep a batch on hand for an easy after-school snack.
Need more recipe ideas for your zucchini? Check these out: Summer Zucchini Galette, Caramelized Onion and Zucchini Quiche
Why you’ll love this recipe!
What ingredients do I need?
- Old-Fashioned Oats: Old-fashioned rolled oats give these bars their hearty, chewy texture. I recommend old-fashioned oats rather than quick oats because they hold their texture better during baking.
- Oat Flour: Oat flour adds tenderness and gives the bars a subtle oat flavor. You can purchase oat flour or make your own by finely grinding old-fashioned oats.
- All-Purpose Flour: All-purpose flour provides structure so the bars hold together well while remaining soft and chewy.
- Baking Powder: Baking powder gives the bars a little lift and helps keep them from becoming overly dense.
- Kosher Salt: Salt balances the sweetness and enhances the flavor of the chocolate and cinnamon.
- Ground Cinnamon: Cinnamon adds a warm, cozy flavor that pairs especially well with zucchini, oats, and chocolate.
- Dark Brown Sugar: Dark brown sugar provides sweetness while adding moisture and a deeper caramel-like flavor.
- Ground Flaxseed: Ground flaxseed adds texture and complements the hearty oat base.
- Egg: The egg helps bind the ingredients together and contributes to the structure and tenderness of the bars.
- Whole Milk: Whole milk adds moisture and richness to the batter.
- Unsalted Butter: Melted butter adds richness and helps create tender, flavorful bars.
- Vanilla Extract: Vanilla enhances the chocolate, cinnamon, and brown sugar flavors.
- Zucchini: Fresh zucchini adds moisture and tenderness. For the best texture, shred it using the large holes of a box grater, lightly salt it, allow it to sit for 10 minutes, and then squeeze out the excess liquid very well.
- Chocolate Chunks: Chopped chocolate creates larger pockets of melted chocolate throughout the bars. Use your favorite semisweet or dark chocolate for a delicious contrast with the sweet, cinnamon-spiced oat base.
- Flaky Sea Salt: The perfect way to balance the sweet! Don’t skip this!
Recipe Variations
- Chocolate Chunk Zucchini Nut Bars: Add ½ cup chopped toasted walnuts or pecans to the batter for a little extra crunch.
- Chocolate Cherry Zucchini Bars: Replace up to half of the chocolate chunks with dried cherries for a sweet-tart combination.
- Coconut Chocolate Chunk Zucchini Bars: Add ¼ cup toasted, unsweetened shredded coconut along with the chocolate chunks.
- Spiced Zucchini Oat Bars: Add ½ teaspoon pumpkin pie spice for another layer of warm spice.
Pro Tips
- Don’t skip squeezing the zucchini! This is probably the most important tip for getting the right texture. Zucchini contains a lot of water, and too much moisture can leave the bars wet or gummy in the center.
- My favorite method: Shred the zucchini using the large side of a box grater, place in a clean towel/cloth over a colander, lightly sprinkle it with salt, let it sit for 10 minutes, and then squeeze out the excess liquid using the clean towel/cloth or your hands. You don’t need to completely dry the zucchini, just remove the excess water. (See below).
- Use the old-fashioned oats. Old-fashioned oats provide a chewy texture and hold up better during baking than quick oats. They also give the bars a more substantial, hearty texture.
- Chop the chocolate roughly into different sizes. This will help with the chocolate distribution, so don’t worry about making every piece exactly the same size. A mixture of smaller pieces and larger chunks gives you chocolate throughout the bars along with a few especially melty pockets.
- Don’t overmix the batter. Once the wet and dry ingredients are combined, stir just until everything comes together. Overmixing can make the bars denser and less tender.
- Don’t skip lining the pan with parchment paper, leaving some overhang on two sides. Once the bars have cooled, you can simply lift them out of the pan and slice them.
- Watch the baking time closely. Start checking the bars around 30 minutes. The edges should be lightly golden and a toothpick inserted into the center should come out with a few moist crumbs but no wet batter.
- Let them cool completely. I know it is tempting to cut into them immediately, especially when you can smell the chocolate baking, but letting the bars cool for 20–30 minutes makes them much easier to slice. They also become chewier as they cool completely.
- Add the flaky sea salt! A small sprinkle of flaky sea salt over the finished bars is optional but highly recommended. It balances the sweetness and makes the chocolate flavor stand out.
How to Prepare the Zucchini
The amount of water in zucchini can vary quite a bit, which is why removing excess moisture is an important step in this recipe.
For the best results, shred the zucchini using the large holes of a box grater. Place the shredded zucchini in a clean kitchen towel, or cloth, in a colander and then sprinkle it with a little salt and let it sit for about 10 minutes. The salt helps draw out some of the zucchini’s excess water. After 10 minutes, use the towel or cloth to squeeze out as much liquid as possible. You want the zucchini to be well squeezed, but not completely dry.
This step helps keep the bars from becoming overly wet or gummy while still allowing the zucchini to contribute plenty of moisture to the finished bars.
Can I Substitute?
Yes! Like always though, any substitutions made to the recipe can result in a change in texture and/or flavor.
- Old-fashioned oats: For the best texture, stick with old-fashioned oats. Quick oats will produce a softer, less chewy texture.
- Oat flour: If you don’t have oat flour, you can make it by blending old-fashioned oats until finely ground. Measure how much for the recipe after grinding.
- Whole milk: 2% milk can be used in a pinch, although whole milk provides a little more richness.
- Unsalted butter: Salted butter can be substituted; if using salted butter, you may want to slightly reduce the added kosher salt.
- Dark brown sugar: Light brown sugar can be substituted, though the finished bars will have a slightly lighter caramel flavor.
- Chocolate: Use semisweet or dark chocolate, chopped into chunks. Chocolate chips can also be substituted if needed.
- Flaxseed: If you don’t have ground flaxseed, you can omit it, although the texture will be slightly different.
Dietary Substitutions
- Egg-Free: You can replace the egg with 1 flax egg. To make a flax egg, whisk together 1 tablespoon ground flaxseed and 2½ tablespoons water. Let the mixture sit for 5–10 minutes, until it thickens and becomes gel-like. Stir the flax egg into the wet ingredients in place of the regular egg.
- The bars may be slightly more tender and have a little less structure than when made with a traditional egg, but this is a simple option if you need an egg-free substitution.
- Vegetarian: These bars are vegetarian as written.
- Dairy-Free: Use your favorite dairy-free butter substitute and dairy-free milk. Be sure to use dairy-free chocolate as well.
- Nut-Free: The base recipe is nut-free as written. If making these for someone with a nut allergy, check the labels on your chocolate and other packaged ingredients for potential cross-contact.
- Gluten-Free: To make these gluten-free, use certified gluten-free old-fashioned oats and oat flour, along with a gluten-free all-purpose flour blend that is suitable for baking. Because gluten-free flour blends vary, the texture may differ from the original recipe.
Leftovers and Storage
- Room Temperature: Store completely cooled bars in an airtight container at room temperature for up to 3 days.
- Refrigerator: For longer storage, refrigerate the bars in an airtight container for up to 1 week. Allow refrigerated bars to come closer to room temperature before serving, or warm them in the microwave for 10–15 seconds for a softer texture.
- Freezer: These bars are also freezer-friendly! Wrap individual bars tightly in plastic wrap and place them in a freezer-safe bag or airtight container. Freeze for up to 3 months. Thaw overnight in the refrigerator or at room temperature. For the best texture, warm a thawed bar in the microwave for 10–15 seconds before serving.
But, I Still Have A Few Questions…
Do I have to squeeze the zucchini for zucchini oat bars?
Yes, I highly recommend it. Zucchini contains a lot of water, and the amount of moisture can vary from one zucchini to another. Removing the excess liquid helps prevent the bars from becoming too wet or gummy.
What is the best way to drain zucchini?
Shred the zucchini using the large holes of a box grater, sprinkle it with salt, and let it sit for about 10 minutes. Then squeeze the zucchini well using a clean kitchen towel, cheesecloth, or your hands. You want to remove the excess liquid without completely drying out the zucchini.
Why do you salt the shredded zucchini before squeezing it?
Salt helps draw moisture out of the shredded zucchini while it rests. After about 10 minutes, you’ll be able to squeeze out more of the excess liquid, which helps give the finished bars a better texture.
Do I peel the zucchini first?
No. There is no need to peel the zucchini. The skin is tender and adds color to the bars. Simply wash the zucchini well, trim the ends, and shred it.
Can I use frozen zucchini?
Fresh zucchini is recommended for the best texture. Frozen zucchini contains a significant amount of water, so if you use it, thaw it completely and squeeze it extremely well before measuring and adding it to the batter. Because the moisture content can vary, the final texture may be different.
Can I use quick oats instead of old-fashioned oats?
You can, but I recommend old-fashioned oats for this recipe. Quick oats absorb moisture differently and will give the bars a softer, less chewy texture.
Can I make my own oat flour?
Absolutely. Add old-fashioned oats to a blender or food processor and blend until they have the consistency of flour. Measure the oat flour after grinding.
What kind of chocolate should I use?
Semisweet or dark chocolate works especially well. Chop a chocolate bar into a mixture of smaller pieces and larger chunks for chocolate throughout the bars and larger melty pockets.
Can I use chocolate chips instead of chocolate chunks?
Yes. Chocolate chips can be substituted for the chopped chocolate in an equal amount.
Can I add nuts to these zucchini bars?
Yes. Add about ½ cup chopped toasted walnuts or pecans along with the chocolate chunks. Toasting the nuts first will give them even more flavor and crunch.
Why are my zucchini bars wet or gummy?
The most common culprit is excess moisture from the zucchini. Make sure you squeeze the shredded zucchini very well before adding it to the batter. Also make sure the bars are fully baked before removing them from the oven. Because ovens and zucchini vary, your bars may need a few additional minutes beyond the minimum baking time.
How do I know when zucchini oat bars are done?
The edges should be lightly golden and the center should look set rather than wet. A toothpick inserted into the center should come out with a few moist crumbs but no wet batter.
Can I make these bars without chocolate?
Yes, although the chocolate adds much of the sweetness and flavor that make these bars feel like a treat. If you leave it out, consider adding nuts, dried fruit, or another mix-in you enjoy.
Can I make these in a different size pan?
An 8×8-inch pan is recommended for the thickness and baking time in this recipe. A different size pan will change the thickness of the bars and may require a different baking time, so watch for the visual doneness cues rather than relying only on the listed time.
Can I double the recipe?
Yes, you can double the recipe, but you’ll need a larger baking pan. The baking time will depend on the size and depth of the pan you use, so check the center for doneness rather than relying on the original baking time.
Can I make these zucchini bars ahead of time?
Yes. These bars are excellent for making ahead. Once completely cooled, store them in an airtight container and enjoy them over the next several days, or freeze them for longer storage.
Can I freeze Chocolate Chunk Zucchini Oat Bars?
Yes! These bars freeze well. Wrap individual cooled bars tightly in plastic wrap and place them in a freezer-safe bag or container. Freeze for up to 3 months.
How do I thaw frozen zucchini bars?
Thaw individual bars at room temperature or place them in the refrigerator overnight. For a warm, bakery-style texture, microwave a thawed bar for about 10–15 seconds before serving.
Are these zucchini bars good for lunchboxes?
Yes. Once completely cooled, they make an easy lunchbox or school snack. If you’re packing them for someone with food allergies, be sure to check the labels of all ingredients, particularly the chocolate.
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Make sure to tag @thehomechefmomma on Instagram or Facebook, and leave a review or comment if you make these. I always get so excited to see your creations, variations of the recipe, and feedback! Just remember to be kind in your comments, there is still a person behind this screen! 🙂
Chocolate Chunk Zucchini Oat Bars
Ingredients
- 1 cup old-fashioned oats
- ½ cup oat flour
- 1 cup all-purpose flour
- 1 teaspoon baking powder
- 1 teaspoon kosher salt
- 1 teaspoon ground cinnamon
- ⅔ cup packed dark brown sugar
- 2 tablespoons ground flaxseed
- 1 large egg
- ½ cup whole milk
- 2 tablespoons unsalted butter melted
- 2 teaspoons vanilla extract
- 2 cups shredded zucchini well squeezed dry (about 2 medium zucchini)
- 2 cups chopped chocolate divided
Instructions
- Preheat the oven to 350°F. Line an 8×8-inch baking pan with parchment paper, leaving an overhang on two sides for easy removal. Lightly coat with nonstick baking spray.
- Shred the zucchini using the large holes of a box grater. Sprinkle the shredded zucchini with salt and let it sit for 10 minutes. Place the zucchini in a clean kitchen towel or colander and squeeze out as much excess moisture as possible. Set aside.
- In a large bowl, whisk together the old-fashioned oats, oat flour, all-purpose flour, baking powder, kosher salt, cinnamon, and ground flaxseed.
- In a separate medium bowl, whisk together the brown sugar, egg, whole milk, melted butter, and vanilla extract until smooth.
- Pour the wet ingredients into the dry ingredients and stir until just combined.
- Fold in the shredded zucchini and 1¾ cups of the chopped chocolate, being careful not to overmix.
- Spread the batter evenly into the prepared baking pan. Sprinkle the remaining ¼ cup chopped chocolate over the top.
- Bake for 30–38 minutes, or until the edges are lightly golden and a toothpick inserted into the center comes out with a few moist crumbs but no wet batter.
- Allow the bars to cool in the pan for 20–30 minutes before lifting them out using the parchment paper. Slice into 16 bars and enjoy.
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Nutritional Content Disclaimer
I choose not to include nutritional information with my recipes, as these values can be calculated from the ingredients provided. With my background as a pediatric nurse practitioner and my own family experience with disordered eating, I understand how focusing on numbers can affect our relationship with food. My philosophy is that all foods have a place—sweet, savory, nourishing, or indulgent. I aim to share recipes that support a healthy, joyful approach to eating. My hope is that this space also encourages a balanced, healthy relationship with food for you and your family too.