If you are anything like me, these Fudgy Fluffernutter Blondies are about to become your new favorite dessert. Rich chocolate, creamy peanut butter, gooey marshmallow fluff, and crunchy Nutter Butter cookies come together in one incredibly indulgent blondie.
The batter starts as a buttery peanut butter blondie before part of it is transformed into a rich chocolate layer with cocoa powder, melted dark chocolate, and chopped dark chocolate that bakes into irresistible melty pockets. Layered between are whole Nutter Butter cookies and frozen dollops of marshmallow fluff, creating gooey pockets of marshmallow in every bite.
One of my favorite tricks for this recipe is freezing spoonfuls of marshmallow fluff before assembling the bars. It makes the fluff much easier to work with and helps create distinct pockets of marshmallow throughout the blondies instead of disappearing into the batter.
The result is a rich, chewy dessert that’s packed with layers of peanut butter, chocolate, marshmallow, and crunchy cookies, all finished with flaky sea salt for the perfect sweet and salty bite. These blondies are guaranteed to disappear fast and perfect for every occasion.
Why you’ll love this recipe!
What ingredients do I need?
- Unsalted Butter: Creates a rich, buttery base while giving the blondies their soft, chewy texture.
- Light Brown Sugar: Adds moisture, chewiness, and a subtle caramel flavor that pairs beautifully with peanut butter.
- Granulated Sugar: Balances the brown sugar while helping create those perfectly chewy edges.
- Creamy Peanut Butter: The star ingredient that gives these blondies their classic Fluffernutter flavor.
- Eggs and Egg Yolk: Provide structure while the extra yolk adds richness and contributes to the fudgy texture.
- Vanilla Bean Paste: Adds deep vanilla flavor and beautiful flecks throughout the batter.
- All-Purpose Flour: Provides enough structure while still keeping the blondies soft and chewy.
- Salt: Balances the sweetness and enhances the chocolate and peanut butter flavors.
- Cocoa Powder: Transforms part of the batter into a rich chocolate layer.
- Dark Chocolate (melted): Adds richness and intensifies the chocolate flavor.
- Chopped Dark Chocolate: Melts into gooey pockets throughout the bars, making every bite extra indulgent.
- Marshmallow Fluff: Creates soft, gooey pockets that perfectly complement the peanut butter and chocolate.
- Nutter Butter Cookies: Add crunch, texture, and even more peanut butter flavor.
- Flaky Sea Salt: The finishing touch that ties all the flavors together.
Recipe Variations
- Milk Chocolate: Change the dark chocolate used to milk chocolate for an even sweeter dessert.
- Holiday Version: Top with festive sprinkles before baking to make these perfect for Christmas, Halloween, birthdays, or game day celebrations.
Pro Tips
- Freeze the marshmallow fluff first. Spoon the fluff into nine dollops on a parchment lined plate or baking sheet and freeze while you prepare the batter. This makes it much easier to press into the blondie layer and creates distinct gooey marshmallow pockets after baking.
- Use chopped chocolate instead of chips if possible. Chopped chocolate melts into beautiful pools throughout the bars, giving them that bakery-style finish.
- Don’t overmix the batter. Mix just until the flour disappears to keep the blondies soft and chewy.
- Need help with melting the chocolate? Check out my guide here.
- Use parchment paper with overhang. This makes lifting the blondies out of the pan easy once they’re cooled.
- Don’t overbake the blondies. The center should still look slightly soft when you remove the pan from the oven. The bars will continue setting more as they cool.
- Cool completely before slicing. This is one recipe where patience pays off. Waiting at least 1–2 hours gives you clean bakery-style slices.
- Wipe your knife between each cut. This keeps the layers looking beautiful and prevents marshmallow from dragging across the bars.
- Finish with flaky sea salt. It enhances every layer and perfectly balances the sweetness.
Can I Substitute?
Yes! Like always though, any substitutions made to the recipe can result in a change in texture and/or flavor.
- Creamy Peanut Butter: Natural peanut butter can be used as long as it has been stirred well, although the texture may be slightly softer.
- Dark Chocolate: Semi-sweet, or milk, chocolate may be substituted for dark chocolate.
- Chopped Chocolate: Chocolate chips can be used in place of chopped chocolate, though chopped chocolate creates richer melted pockets.
- Vanilla Bean Paste: Vanilla extract can be substituted.
- Light Brown Sugar: If you don’t have light brown sugar, dark brown sugar works just as well.
Dietary Substitutions
- Vegetarian: This recipe is naturally vegetarian.
- Gluten-Free: Substitute a 1:1 gluten-free baking flour and use gluten-free sandwich cookies in place of the Nutter Butters.
- Nut-Free: Unfortunately, this recipe relies heavily on peanut butter and peanut butter cookies, so it isn’t recommended for nut-free substitutions.
Leftovers and Storage
- Room Temperature: Store the blondies in an airtight container for up to 4 days. Place a sheet of parchment paper between layers if stacking to prevent them from sticking together.
- Refrigerator: For an even fudgier texture, refrigerate the blondies for up to 1 week.
- Freezer: Freeze completely cooled blondies individually wrapped or layered with parchment paper in an airtight container for up to 3 months. Thaw overnight in the refrigerator or for about an hour at room temperature before serving.
- Serving Tip: These bars are delicious at room temperature, but if you’d like them extra gooey, microwave an individual blondie for about 10–15 seconds before serving.
But, I Still Have A Few Questions…
Why should I freeze the marshmallow fluff first?
Freezing the marshmallow fluff is one of my favorite tricks for this recipe. Instead of it disappearing into the batter, the frozen dollops hold their shape as you assemble the blondies, creating beautiful pockets of gooey marshmallow throughout the finished bars.
Can I skip freezing the marshmallow fluff?
You can, but I don’t recommend it. Marshmallow fluff is extremely sticky and difficult to work with straight from the jar. Freezing it for just a short time makes assembling the layers much easier.
Why is only part of the batter chocolate?
Keeping part of the batter as a peanut butter blondie allows both flavors to shine. The chocolate layer adds richness while the peanut butter layer keeps the bars soft, buttery, and full of classic Fluffernutter flavor.
Can I substitute chocolate chips for chopped chocolate?
Yes, but chopped chocolate melts into larger, richer pools throughout the blondies, giving them a bakery-style finish. Chocolate chips tend to hold their shape more during baking.
How do I know when they’re done baking?
The edges should look set while the center still appears slightly soft. A toothpick inserted into the middle should come out with moist crumbs. The blondies will continue to set as they cool.
Why do I need to let them cool before slicing?
Cooling allows the chocolate, marshmallow, and blondie layers to firm up, giving you clean slices instead of a gooey mess. As tempting as it is to dig in right away, patience really pays off here.
Can I make these ahead of time?
Absolutely! In fact, I think they’re even better the next day. The flavors deepen overnight, and the texture becomes even fudgier.
Can I freeze these blondies?
Yes! Once completely cooled, wrap the blondies individually or layer them between sheets of parchment paper in an airtight container. Freeze for up to 3 months.
Can I use crunchy peanut butter?
You can, but creamy peanut butter gives these blondies the smooth, fudgy texture they’re known for.
Why are these called blondies instead of brownies?
While these bars have rich chocolate layers, the base of the recipe is a buttery peanut butter blondie batter. The result is a fudgy blondie with chocolate rather than a traditional brownie.
Let’s engage!
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! 🙂
Fudgy Fluffernutter Blondies
Ingredients
Peanut Butter Blondie Batter
- 1 cup unsalted butter melted
- ¾ cup packed light brown sugar
- ¾ cup granulated sugar
- ½ cup creamy peanut butter
- 2 large eggs
- 1 egg yolk
- 2 teaspoons vanilla bean paste or vanilla extract
- 1½ cups all-purpose flour
- 1 teaspoon salt
Chocolate Batter (added to ⅔ of the peanut butter batter)
- ⅓ cup unsweetened cocoa powder
- 2 ounces dark chocolate melted
- 6 ounces dark or semi-sweet chocolate chopped
Layers
- ½ cup marshmallow fluff divided
- 12 whole Nutter Butter cookies
- 6 Nutter Butter cookies crushed
- Flaky sea salt for finishing
Instructions
Prepare the Pan
- Preheat the oven to 325°F.
- Line an 8×8-inch baking pan with parchment paper, leaving enough overhang to lift the blondies out after baking.
Freeze the Marshmallow Fluff
- Line a small plate or tray with parchment paper.
- Using two spoons, portion the marshmallow fluff into 9 equal dollops.
- Place in the freezer while preparing the batter.
Make the Blondie Batter
- In a large mixing bowl, use a hand mixer on medium speed to beat together the melted butter, brown sugar, and granulated sugar until smooth and glossy.
- Beat in the peanut butter until fully incorporated.
- Then add the eggs, egg yolk, and vanilla bean paste and beat again for about 1–2 minutes until the mixture becomes slightly lighter and smooth.
- Add in the flour and salt. Mix just until no dry streaks remain. Do not overmix.
Make the Chocolate Batter
- Divide the batter, setting aside about one-third of the blondie batter.
- To the remaining two-thirds of the batter, beat in the cocoa powder and melted dark chocolate until fully incorporated.
- Fold in the chopped chocolate.
Assemble
- Spread about two-thirds of the chocolate batter evenly into the prepared pan.
- Arrange the whole Nutter Butter cookies in an even layer.
- Then spoon the reserved peanut butter blondie batter onto the cookies and spread evenly.
- Remove the marshmallow fluff from the freezer and gently press the frozen dollops into the blondie layer.
- Spread the remaining chocolate batter over the top.
- Finish with the crushed Nutter Butter cookies.
Bake
- Bake for 32–38 minutes, or until the edges are set and the center still looks slightly underbaked.
- A toothpick inserted into the center should come out with moist crumbs, not wet batter.
Cool
- Sprinkle with flaky sea salt and allow the blondies to cool completely in the pan for at least 1–2 hours.
Notes
- Freezing the fluff: This simple step makes assembling the blondies much easier and helps create distinct gooey marshmallow pockets after baking.
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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.