Preheat oven to 350 and grease a 9 inch springform pan generously.
Pour prepared brownie mix into pan and bake for 20 mins until just set on top. Let cool 2 mins. Lower oven to 325.
While it is baking prepare the cheesecake.
Beat cream cheese and sugar.
Add eggs and vanilla until smooth.
After you cool the brownie 2 mins, very slowly and carefully scoop the cheesecake mix on top. Some brownie may bubble up, that's ok but go slowly to avoid too much of this.
Bake entire cake at 325 for 50 mins.
Cool and chill overnight.
