Blackout Chocolate Banana Bread

Preheat oven to 350°. Lightly coat a 9x5" loaf pan with nonstick spray. Line bottom of pan with parchment paper, leaving a generous overhang on long sides.

Whisk all-purpose flour, whole wheat flour, cocoa powder, baking soda, baking powder, and salt in a medium bowl.

Mash 4 bananas with a potato masher or fork in a medium bowl until smooth. Using an electric mixer on medium-high speed (or a stand mixer fitted with the paddle attachment), beat brown sugar and butter in a large bowl until light and fluffy, about 4-5 minutes. Add eggs one at a time and beat until incorporated, scraping down sides of bowl if needed. Reduce speed to medium-low, add sour cream, vanilla, and mashed bananas; beat until combined. The mixture may look grainy and broken at this point, but don’t fret! It will emulsify when the dry ingredients are added.

Reduce mixer speed to low and gradually add dry ingredients, beating just until incorporated (do not overmix or cake will become tough). Fold in chocolate.

Scrape batter into prepared pan and smooth top. Slice remaining banana lengthwise into 3 equally thick planks and place on top of cake, cut sides up. Sprinkle batter, as well as bananas, with demerara sugar.

Bake cake until a tester inserted into the center comes out clean (there may be some melted chocolate residue left on the tester, which is fine), 65–75 minutes.

Transfer pan to a wire rack and let cake cool completely. Using parchment overhang, lift cake from pan and serve.