Frosted Banana Bars

Honestly, this is pretty much a decadent cake disguised as innocent bars that sound like they might even possibly be healthy. Don't be fooled...

1/2 cup butter, softened
1 1/2 cups sugar
2 eggs
1 cup sour cream(can substitute yogurt)
1 tsp vanilla
2 cups flour
1 tsp baking soda
1/4 tsp salt
3 bananas, well smashed
Frosting:
8 oz cream cheese, soft
1/2 cup butter, soft
2 tsp vanilla
4 cups powdered sugar
milk

Cream butter and sugar. Add eggs, sour cream and vanilla. Combine flour, baking soda and salt; gradually add to the creamed mixture. Stir in bananas. Spread into greased 9x13 pan. Bake at 350 about 20 minutes until middle doesn't jiggle when you shake pan. Cool. For frosting, beat cream cheese, butter and vanilla. Beat in powdered sugar. If too thick, thin with milk. Can mix in cinnamon to flavor frosting.