Mix butter, sugar, and vanilla. Beat in eggs till well blended. Stir in flour, cocoa, baking powder, and salt. Blend well.
Step 2
Reserve 2 cups of batter, set aside
Step 3
Grease 13x9x2 inch pan. Spread remaining batter in prepared pan. Arrange peppermint patties in a single layer over batter about 1/2 inch apart.
Step 4
Spread reserved 2 cups batter over patties. Bake 350 degrees F (175 degrees C) for 50-55 minutes till brownies begin to pull away from sides of pan. Cool completely in pan on wire rack. Enjoy!!!