Chocolate banana cake layers with a peanut butter banana cream filling and chocolate and peanut butter buttercreams.
Preheat your oven to 325 degrees F. Spray three 8-inch pans or four 6-inch pans with nonstick spray, line the bottom with parchment paper and spray again. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and the sugars on medium-high speed until light and fluffy, about 2 minutes.
Gradually add the eggs, scraping the sides of the bowl with each addition, Mix for about 2 minutes on medium speed after all the eggs are added.
Add the mashed bananas and vanilla. Stir until combined.
In a medium sized mixing bowl, whisk the flour, cocoa, baking powder, baking soda and salt.
In a small mixing bowl, combine the buttermilk and sour cream. Whisk to combine.
With the stand mixer on low speed, alternately add the the flour mixture and the buttermilk mixture, starting and ending with the flour. Mix just until the ingredients are combined.
Stir in chocolate chips by hand.
Divide the batter between the three 8-inch pans (about 20 ounces in each), and bake for about 30 to 33 minutes, or until a toothpick inserted in the center of the cake comes out with a few moist crumbs on it.
Let the cakes cool in the pans for 15 minutes and then invert onto wire cooling rack to cool completely.
Cake layers can be made ahead of time and wrapped in plastic wrap and stored in the freezer. Allow the cake layers to thaw for about 30 minutes before you stack and decorate the cake.
I do NOT recommend using bake even strips on my cakes.
This is best made the day before you want to assemble your cake, but do not add the bananas until you're ready to assemble and serve.
In a medium-sized mixing bowl, combine the pudding mix, sweetened condensed milk, peanut butter and milk. Whisk until pudding dissolves and the mixture is uniform. Cover and place in the refrigerator until the mixture sets.
Meanwhile, whip your whipping cream until stiff peaks form.
Once your pudding mixture has set, fold in the whipped cream to the pudding.
Do not add fresh bananas yet. Cover the banana cream filling and refrigerate overnight.
Heat the cream in the microwave for about 45 to 60 seconds. Pour the cream over the chocolate chips to melt. Stir until smooth and silky. Set aside.
In the bowl of a stand mixer, fitted with the paddle attachment, cream the butter for about 2 minutes on medium-high speed.
Slowly add the chocolate mixture, making sure to scrape down the sides of the bowl a few times. Mix on medium speed for about a minute after all the chocolate is added.
Mix in the vanilla and pinch of salt.
With the mixer on slow speed, gradually add the powdered sugar. Once all of the powdered sugar is added, mix the buttercream for another few minutes on medium-high speed. You'll notice the color lighten - don't worry, it darkens as it sits out after you decorate your cake.
Buttercream can be made ahead of time and stored in an airtight container in the refrigerator. Allow the buttercream to reach room temperature before using and make sure to re-beat it for a bit.
If you buttercream seems soft, refrigerate for a bit.
In the bowl of electric mixer fitted with the paddle attachment, combine the butter and peanut butter. Beat on medium-high speed until smooth, about 45 seconds.
Add the powdered sugar to the bowl and mix in, slowly at first until incorporated, then increasing the mixer speed to high. Blend in the vanilla extract, salt and heavy whipping cream, and continue to whip on high speed until very fluffy, about 4-5 minutes, scraping down the sides of the bowl as needed.
Beat frosting by hand with a wooden spoon to get air bubbles out.
Place the first cake layer, top side up, on a cake board or cake plate. Pipe a rim of chocolate buttercream around the edge of the cake. This will act as a barrier to the peanut butter banana cream filling.
Evenly spread about 1 cup of peanut butter banana cream filling over the cake layer. If you're serving the cake same day, add sliced bananas, otherwise, leave the bananas out.
Repeat these steps for the second cake layer.
Place the final cake layer, top side down, on the filling. Apply a thin layer of chocolate buttercream around the entire cake. This is your crumb coat. Freeze the crumb-coated cake for 10 to 15 minutes.
Once the crumb coat is set, continue to frost your cake with the remaining chocolate buttercream and the peanut butter buttercream.