Step 1

Preheat the oven to 350°F. Butter and flour two 8-inch round cake pans.

Step 2

In a medium bowl, sift together the flour, cinnamon, baking powder, baking soda, and salt.

Step 3

In the bowl of an electric mixer, beat the butter and sugars on medium-high speed until light and fluffy, about 3 minutes. Add in the vanilla and then the eggs, one at a time. On low speed beat in half the dry ingredients then the sour cream and bananas. Beat in the remaining dry ingredients. Stir in the chocolate chips.

Step 4

Divide the batter among the prepared pans. Bake for 35 to 40 minutes, or until the cakes are golden brown and pull away from the edges. Cool in the pans for 15 minutes before flipping onto cooling racks to cool completely. Refrigerate until ready to frost. The colder the cake, the easier it will be to frost. You can even pop the cake in the freezer for 30 minutes to chill.

Step 5

In the bowl of an electric mixer, beat the butter and peanut butter on medium-high speed until light and fluffy. Add the vanilla, salt, and powdered sugar and continue beating until the frosting is smooth and fluffy.

Step 6

Place one cake layer on a cake turntable or cake stand. For a smooth and even frosting coverage, use a pastry bag and open tip to pipe a generous ring of the frosting around the top edge of the cake layer. Fill up the frosting ring with additional frosting, spreading to create an even layer. Place the other cake layer upside-down on top of the frosting so that the top of the cake is nice and flat. With an offset spatula, spread the remaining frosting evenly all over the cake, smoothing the edges. Place chocolate chips along the bottom of the cake for garnish. Serve or cover and store in the fridge for up to 2 days. Let come to room temperature for an hour before serving.