Banana Sheet Cake with Cream Cheese Frosting

1/2 cup melted butter
1 1/2 cup sugar
2 eggs
1 cup sour cream
1 tsp vanilla
2-3 medium ripe bananas, mashed
2 cups flour
1 tsp baking soda
1 tsp baking powder
1/4 tsp salt

Beat butter, sugar and eggs. Add sour cream, vanilla & banana and mix well. Add dry ingredients. Spread batter into a greased large cookie sheet. Bake at 300 for 25-30 minutes.

Frosting:
8 oz cream cheese, softened
1/2 tsp vanilla
1/3 cup soft butter
3 cups powdered sugar

Spread on cooled cake. Keep cake refrigerated.