Peanut Butter Cake Bars

2/3 cup butter, softened
2/3 cup peanut butter, softened
1 cup sugar
1 cup brown sugar
4 eggs
1 tsp vanilla
2 cups flour
2 tsp baking powder
1/2 tsp salt
1 pkg milk chocolate chips

In a large bowl, cream the butter, peanut butter, sugar, and brown sugar. Add eggs one at a time, beating well after each addition. Beat in vanilla. Combine the flour, baking powder and salt; gradually add to creamed mixture. Stir in chocolate chips.

Spread into greased 9x13 baking pan. Bake at 350 for 35-45 minutes or until a tooth pick inserted into the center comes out clean. Cook on wire rack. Cut into bars and serve.