Chocolate Banana Layered Cake Recipe

Preheat and prepare pans

Preheat the oven to 350°F (175°C). Grease two 8-inch round cake pans (or three 6-inch) with nonstick spray or butter and line the bottoms with parchment circles if available.

Mix dry ingredients

In a large bowl, sift or whisk together 2 cups all-purpose flour, 3/4 cup cocoa powder, 1.5 cups granulated sugar, 1.5 tsp baking powder, 1 tsp baking soda, and 1/2 tsp salt until evenly combined.

Combine wet ingredients

In a separate bowl or large measuring cup, whisk together 2 eggs, 1 cup buttermilk, 1/2 cup vegetable oil, and 1 tsp vanilla extract until smooth.

Bring batter together

Pour the wet ingredients into the dry ingredients and stir with a spatula until mostly combined. Slowly add 3/4 cup hot water or hot coffee while stirring; the batter will be thin. Scrape the bowl and mix just until smooth and homogeneous—do not overmix.

Bake

Divide batter evenly between prepared pans. Bake on the center rack for 25–30 minutes for 8-inch pans (or 18–22 minutes for 6-inch), until a toothpick inserted into the center comes out with a few moist crumbs. Rotate pans halfway through if your oven has hot spots.

Cool

Allow cakes to cool in pans on a wire rack for 10 minutes, then run a knife around the edges, invert onto racks, remove parchment, and let cool completely before assembling (about 1 hour).

While the cake bakes or cools, prepare the banana filling. Peel and mash 2 ripe bananas until smooth (about 1 cup mashed). Stir in 1/4 cup light brown sugar, 1 tsp lemon juice, and 1/4 tsp ground cinnamon until evenly combined. Taste and adjust sweetness; the lemon prevents browning and brightens flavor. If the mixture seems very wet, drain a little liquid, but it should remain spreadable.

If using banana slices between layers, slice one banana just before assembly to avoid browning and toss lightly with a little lemon juice.

Make buttercream

In a large bowl, beat 3/4 cup softened unsalted butter with an electric mixer on medium speed until creamy (about 1–2 minutes). Sift in 3 cups powdered sugar and 3/4 cup cocoa powder to avoid lumps. Beat on low to combine, then add 1 tsp vanilla, 3 tbsp heavy cream (add more later if needed), and 1/8 tsp salt. Increase speed to medium-high and beat until light and fluffy, about 2–3 minutes. If frosting is too stiff, add cream 1 teaspoon at a time until spreadable; if too thin, add a little more powdered sugar.

Level and layer

If cake tops domed, level them with a serrated knife so layers stack evenly. Place the first cake layer on a cake board or serving plate. Spread about one-third of the chocolate frosting in an even layer. Spread half of the mashed banana mixture over the frosting (or place banana slices), leaving a small border to prevent seepage. Add a thin layer of frosting on top of the banana if desired to seal.

Place the second cake layer on top and repeat: spread another third of the frosting, then the remaining mashed banana (or banana slices). Top with the final cake layer. Use remaining frosting to crumb-coat the cake (a thin layer all over) and chill 15 minutes for a firm base, then apply the final frosting layer smoothly with an offset spatula.

Finish and garnish: Press chocolate shavings or sprinkles around the sides or top. Arrange fresh banana slices on top just before serving to avoid browning. Refrigerate leftovers; bring to room temperature before serving for best texture (about 30 minutes).