Peppermint Patty Brownies

1 1/2 cup butter
3 cup sugar
5 eggs
1 tbsp vanilla
2 cups flour
1 cup cocoa
1 tsp baking powder
1 tsp salt
1 package peppermint patties

In a large bowl cream butter and sugar. Add eggs. Beat in vanilla. Combine dry ingredients, add to creamed mixture.
Spread 2/3 of the batter into a 13x9 pan. Arranged peppermint patties over top. Carefully spread remaining batter over the patties. Bake at 350* for 35-40 minutes.