Cordon Rose Banana Cake (from the cake bible)
For the cake:
2 cups sifted cake flour
¾ cup plus 2 Tbs sugar
1 tsp baking soda
¾ tsp baking powder
½ tsp salt
2 large ripe bananas (about 225 grams, peeled)
½ cup sour cream (not low- or non-fat)
2 large eggs
1 ½ tsp pure vanilla extract
10 Tbs unsalted butter, at room temperature
2 tsp grated lemon zest (orange zest will also work)
For the frosting:
1 stick salted butter (if using unsalted, add 1/2 tsp of salt)
1/2 cup packed light brown sugar
1/2 cup packed dark brown sugar
1/4 cup whole milk
2 cups confectioners sugar, must be sifted!
1 tsp. vanilla
Preheat the oven to 350 degrees Fahrenheit.
Spray a 9-inch round springform pan with cooking spray, line the base with a round of parchment paper, and spray the parchment paper.
In a large bowl, whisk together the flour, sugar, baking soda, baking powder, and salt. Set aside.
In a food processor, purée the banana and sour cream until completely smooth. Add the eggs and vanilla & lemon zest, and process briefly to combine. The puréed mixture will be light yellow and quite loose.
Add the softened butter and about ½ of the puréed mixture to the dry ingredients in the bowl. Beat to combine on low speed; then increase the speed and beat for about 90 seconds to aerate the cake structure. Scrape down the sides of the bowl with a rubber spatula, and add the rest of the purée, beating to combine well. The batter will be light tan in color and should be smooth and creamy.
Pour and scrape the batter into the prepared pan. Bake for 35-45 minutes, until the cake is golden and a toothpick inserted in the center comes out clean and dry. Remove the cake from the oven, let cool for 10 minutes while you make the frosting (below), and then remove the rim of the pan. Invert the cake onto a wire rack, and carefully remove the base of the pan and the parchment paper. Turn onto a cake platter.
For the frosting:
Heat butter and brown sugars over medium until the mixture comes to a boil about 2 minutes. Add the milk, stir, and bring the mixture back to a boil, then remove the pan from the heat. Add the confectioners’ sugar and vanilla. Beat with a wooden spoon or whisk until smooth. Use immediately, while it and cake are still warm, and spread quickly before cool.
Allow the cake to sit at room temperature for at least a half hour before serving.