1. Preheat oven to 375°.
2. Grease 13x9 pan.
3. In a large bowl whisk together butter, sugar and vanilla.
4. Add eggs and whisk until well blended.
5. Stir in flour, cocoa, baking powder and salt.
6. Mix well and reserve 2 cups.
7. Spread batter in greased pan.
8. Arrange the patties in a single layer.
9. Spread reserved batter on top.
10. Bake for 50-55 minutes.