Preheat the oven to 350°F. Grease an 8½ x 4½-inch loaf pan and line it with parchment paper.

In a large mixing bowl, beat the butter for about 1 minute until smooth and creamy.

Add the granulated sugar and brown sugar. Beat for 2–3 minutes until light and fluffy.

Beat in the eggs one at a time, mixing well after each addition. Add the egg yolk and mix until fully incorporated.

Mix in the sour cream, milk, vanilla bean paste, and almond extract until just combined.

In a separate bowl, whisk together the flour, cornstarch, baking powder, baking soda, and salt.

Add the dry ingredients to the wet ingredients and mix just until combined.

Toss the chocolate chips with 1 tablespoon flour, then gently fold them into the batter.

Transfer the batter to the prepared loaf pan and smooth the top.

For a bakery-style split, lightly run a butter knife or offset spatula down the center of the batter.

Bake for 55–60 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs attached.

Cool in the pan for 10–15 minutes before transferring to a wire rack to cool completely.

Slice and enjoy.