I made this recipe from a bunch of different recipes, putting them all together into one, uber-decadent cake. I was looking for an interesting cake; something outside of the box (get it? Ha!). This is the result of that. I love bananas, learned that I actually liked walnuts, and learned that brown butter is actually the best thing on this planet. Seriously.
The icing gets a little bit greasy because it’s so densely… butter. Don’t let the cake warm up too much or the icing will melt. If you’re not into dense, thin frosting and would prefer a fluffy buttercream, I’m sure that would be awesome too. I won’t be offended by the fact that you don’t want to try my brown butter icing. Okay, I might be a little offended.
This cake has a lot of steps, but I thought it was really fun.
For the Cake:
~4 cups all-purpose flour
~2 teaspoons baking powder
~1 teaspoon salt
~1 cup browned butter, cooled (see my “Browned Butter” blog post for how to make browned butter)
~2 cups light brown sugar
~4 tablespoons milk or buttermilk
~2 cups mashed banana (about 4 large bananas)
~3 teaspoons vanilla extract
~1 cup chopped walnuts (optional)
For the Icing:
~14 tablespoons unsalted browned butter (see my “Browned Butter” blog post for how to make browned butter)
~3 ½ cups sifted confectioners’ sugar
~3 ½ teaspoons pure vanilla extract
~3 to 5 tablespoons milk
For the Caramelized Walnuts (optional):
~½ cup sugar
~10 well-shaped, large walnut halves
First, toast the walnuts for the cake batter. All you have to do is set a frying pan over medium heat and place the walnuts in the pan. Cook, stirring occasionally, until you can smell them, and the nuts have deepened in color. It’s okay to under-toast them, but don’t burn them. Place the toasted walnuts in a bowl.
For the Cake: Preheat the oven to 350 F. Lightly grease 2 9-inch round baking pans. In a medium bowl, whisk together flour, baking powder, and salt. In a large bowl, whisk together brown sugar, mashed banana, egg, milk and vanilla extract. Whisk in the cooled brown butter. Whisk in the flour mixture gradually, mixing only until no streaks of dry ingredients remain. Fold in chopped toasted walnuts, if using, then pour batter into prepared pans.Bake for about 30 minutes, until a toothpick inserted into the center of the cake comes out clean or with only a few moist crumbs attached. Allow to cool completely before frosting.
For the Frosting: Place cooled brown butter, vanilla, sugar, and 3 tablespoons milk into a medium bowl; stir until smooth. If the icing is too thick, add the remaining 2 tablespoons milk, a little at a time, until the consistency is spreadable.
For the Caramelized Walnuts on top (optional): In a small skillet, melt sugar over medium-high heat until medium golden, about 3 minutes. remove skillet from heat. Working quickly, drop walnut halves, one at a time, into the melted sugar. If the sugar hardens, return skillet to low heat, and stir several minutes. using a fork, turn walnuts until they are evenly coated. Transfer to a wire rack to cool completely (or a plate, whatever). Use to decorate cake.
Assembly: Place one cake layer on a plate (be aware that this will be the plate you will serve the cake on; make it a pretty one!). Spread a little bit of the cooled frosting on top, just barely enough to cover the top of the cake, maybe even less than that. Place the second cake layer on top of the first, and frost the top and sides of the cake with the rest of the frosting. Place the 10 caramelized walnut halves on top, spacing evenly. Place cake in fridge until 30 minutes before serving. 30 minutes before serving, take the cake out of the fridge to bring it back to room temperature.