Makes 2 1/2 to 3 dozen
1/2 cup butter or margarine, 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
Preheat oven to 350 degrees F.
Grease 13x9 cake pan.
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 cake pan.
Spoon remaining batter on top and swirl with a knife.
Bake for 25 minutes or until the bars test done.