The Black bottom banana bars stay very moist, and their rich banana and chocolate flavor is even better the second day. My mother-in-law gave me this recipe, and it’s a special treat for my husband and two sons. from "Rene Wright of Ferryville Wisconsin"

Ingredients 

1/2 cup butter, softened

1 cup sugar

1 egg

1 teaspoon vanilla extract

1-1/2 cups mashed ripe bananas (about 3 medium)

1-1/2 cups all-purpose flour

1 teaspoon baking powder

1 teaspoon baking soda

1/2 teaspoon salt

1/4 cup baking cocoa

Method 

In a mixing bowl, cream butter and sugar. Add egg and vanilla; beat until thoroughly combined. Blend in the bananas.

Combine the flour, baking powder, baking soda and salt; add to creamed mixture and mix well.

Divide batter in half. Add cocoa to half; spread into a greased 13-in. x 9-in. x 2-in. baking pan. Spoon remaining batter on top and swirl with a knife.

Bake at 350° for 25 minutes or until a toothpick comes out clean. Cool. Yield: 2-1/2 to 3 dozen.