Preheat oven to 350°F.
Butter a 9-inch springform pan (must be about 3" tall or overflow problems!), line with a parchment round and butter the parchment. *Note, some people had trouble with a 9inch pan so you may want to try a 10 inch but mine worked perfectly in the 9 inch and many commented it worked fine for them, too. Just a heads up!
Stir together butter, sugar and vanilla in a bowl.
Add eggs.
Stir in flour, cocoa, baking powder and salt.
Spread in prepared pan. Bake about 25 minutes.
Remove from oven and sprinkle on choc chips, peanut butter chips and the peanut butter cups. Lower oven to 325!!!!! Pour the cheesecake batter right on top (directions below)