The Kitchn: This chocolate sheet cake is the best use for ripe bananas
Butter or cooking spray, for coating the pan
12 tablespoons (1 1/2 sticks) unsalted butter, at room temperature
3/4 cup granulated sugar
3/4 cup packed light brown sugar
3 large eggs
2 cups mashed bananas (from 4 to 5 large bananas)
2 teaspoons vanilla extract
3 cups all-purpose flour
1/4 cup unsweetened cocoa powder
1 1/2 teaspoons baking soda
...continued