This banana layer cake recipe is moist, delicious, and so easy to stack into a layers cake!!
Preheat oven to 350°F. Line three 8 inch pans with parchment rounds, and grease with non-stick cooking spray.
Mix together all dry ingredients (flour, baking powder, sugar, and salt) in a stand mixer with a paddle until fully combined.
Mix chunks of room-temperature butter slowly into the dry mix, on a low speed. Continue to mix until no large chunks of butter remain, and the mixture becomes crumbly.
Pour in egg whites, and mix on low until just incorporated. Next, mix in the bananas and buttermilk in two installments, on a low speed.
Add in vanilla and oil, and mix at a low speed until fully incorporated. Scrape down the sides of the bowl with a spatula, then beat on medium speed for about 30 seconds.
Divide batter evenly between the prepared cake pans. I like to use a digital kitchen scale to weigh my pans, and ensure they all have the same amount of batter. This guarantees your layers will bake to be the same height.
If desired, add spoonfuls of warmed Nutella (heated in the microwave for 15 seconds) on top of the banana cake batter. Use a small offset spatula or butter knife to drag horizontal and vertical lines through the batter, to create a swirled pattern with the Nutella.
Bake for 30-32 minutes (or until a skewer comes out clean). Allow to cool for 10 minutes, then run an offset spatula around perimeter of the pan to separate the cake from the pan. Place cake layers into the freezer for 45 minutes, to accelerate the cooling process.
NOTE: Be sure your bananas are SUPER ripe! Yellow bananas will not yield the same results as fully brown bananas.