Yield: makes two 8-inch round cakes
Preheat oven to 350 degrees F. Butter two 8-inch cake pans and line with parchment paper. Set aside.
In a bowl, whisk together flour, baking powder, baking soda, salt and cinnamon. Set aside.
In a bowl of stand mixer fitted with a paddle attachment, cream butter. Once smooth, add brown sugar and mix until combined. Add eggs one at a time, making sure each egg is incorporated before adding the next.
Alternate adding the dry flour mixture and the buttermilk. Start with 1/3 of the flour mixture. Mix on low speed until almost combined. Add 1/2 of the buttermilk. Mix until almost combine. Repeat and end with the dry mixture.
Add the mashed bananas, rum and walnuts. Stir until walnuts are distributed.
Divide cake batter evenly between the two prepared cake pans. Bake for 30-35 minutes until toothpick inserted in center of cake comes out clean and cake springs back to touch. Let cakes cool in pan for 15 minutes. Then run an offset spatula or knife around the perimeter of cake and invert cake onto cooling rack. Allow cake to cool to temperature.
In the bowl of a stand mixer fitted with a paddle attachment, whip cream cheese until smooth. Scrape down bowl as necessary to ensure thorough mixing. Add butter and mix until incorporated. Add light brown sugar, confectioners' sugar, salt, cinnamon and rum. Mix until smooth.
Once cakes have cooled to room temperature, if desired, slice cake into two layers. You will end up with 4 layers.
Place first layer on cake stand. Scoop about 1/2 cup of cream cheese icing on cake. Smooth into an even layer using an offset spatula. Place next cake layer on top. Add another 1/2 cup of icing and smooth into an even layer. Continue until all cake layers have been used.
Keep cake in the fridge until ready to serve. Take cake out 20 minutes before serving and let sit at room temperature to slightly soften. Garnish cake with sprinkles if desired.
BANANA RUM CAKE ADAPTED FROM JOY THE BAKER COOKBOOK