- 3 cups all purpose flour
- 1 tablespoon baking powder
- ½ teaspoon salt
- ⅓ cup cocoa
- 3 sticks unsalted butter, softened
- 2 cups granulated sugar
- 4 large eggs
- 1 teaspoon pure vanilla extract
- 1 cup milk
- ¾ cup chunky peanut butter
- 1 cup brown sugar
- 4 bananas, halved lengthwise
- Preheat the oven to 180C and lightly grease or butter the sides of a 9×13 glass baking dish. In a medium bowl, whisk the flour with the baking powder, salt, and cocoa.
- In a standing electric mixer, beat 2 sticks of butter with the granulated sugar at medium speed until very fluffy, about 5 minutes. Beat in the eggs one at a time. Add the vanilla. Beat in the flour mixture and the milk.
- In a small bowl, blend the remaining stick of butter with the brown sugar and spread it in the baking dish. Arrange the bananas, cut sides down, in the dish. Spoon dollops of the peanut butter into the dish and fill in the gaps with the chocolate batter. Bake for 45 minutes. Let the cake cool for 10 minutes, then loosen the edges with a knife and invert in onto a platter. Let the cake cool slightly, then cut into squares and serve.
For an extra gooey addition: mix 4 tablespoons of butter with ⅓ cup brown sugar and ½ teaspoon vanilla, then melt it in the microwave for 20 seconds at a time, stirring after each interval, for a total of 1 minute. Pour the warm sauce over the cake.