Based on Baggett’s “The All American Dessert Book”
- 2 ⅓ cups unsifted cake flour
- ¾ tsp baking powder
- ½ tsp baking soda
- Scant ½ tsp salt
- ⅔ cup (10 ⅔ Tbsp) unsalted butter, slightly softened
- 1 ½ cups granulated sugar
- 2 large eggs plus 1 large egg yolk
- ½ cup sour cream
- 1 ¼ cups well-mashed overripe bananas (4 – 5 medium bananas)
- 2 tsp vanilla extract
- 1 ¼ tsp instant espresso powder or granules, dissolved in 1 ½ Tbsp hot water
- 1 ½ Tbsp unsweetened Dutch-process cocoa powder
- ⅓ cup (5 ⅓ Tbsp) unsalted butter, slightly softened
- ½ tsp vanilla extract
- 1 ½ cups confectioner sugar, sifted after measuring if lumpy
- 1-2 tsp water, if needed
- Position rack in middle of the oven and preheat to 350 F
- Generously grease 9 x 13 in baking dish
- Sift together the flour, baking powder, baking soda, and salt into a medium bowl, then stir well.
- In a large bowl, combine the butter and sugar. Beat with a mizer on medium speed until the mixture is well blended and lightened, about 1 ½ minutes, scarping down the sides of the bowl as needed.
- Add the eggs and yolk, beating until well blended, about 30 seconds.
- Add the sour cream and continue beating for 1 minute longer or until smoothly incorporated, scraping down the sides of the bowl as needed.
- Reduce the mixer speed to low. Add half the flour mixture, beating just until incorporated.
- Beat in the mashed bananas and vanilla until smoothly incorporated.
- Beat in the remaining flour mixture until the batter is well blended and smooth, scarping down the sides of the bowl as needed.
- Turn out the batter into the pan, spreading it evenly to the edges. Bake for 20 to 30 minutes, or until the top is browned and springs back slightly when pressed, and a toothpick inserted in the center comes out clean. The sides of the cake swill begin to draw away from the pan sides.
- Transfer to a wire rack. Let cool completely, at least 1 hour.
- In a large bowl with mixer on low, then medium speed, beat together the espresso mixture, cocoa powder, butter, and vanilla until very well blended and smooth, scraping down the sides of the bowl as needed.
- On low, then medium speed, beat in the confectioner sugar until the icing is very smooth, scraping down the sides of the bowl several times.
- The icing should be slightly soft and spreadable; if necessary, beat in a teaspoon or two of water.
- Immediately spread the icing evenly over the cake top in the pan using an offset spatula or table knife. Let stand for a few minutes until the icing sets before cutting.
- We reduced the sugar a bit.
- You can use a fudge glaze or rich and creamy chocolate fudge frosting instead of the mocha icing.