Preheat oven to 325 degrees F.
In a large bowl, beat cream cheese and peanut butter for 1 minute. Add sugar, salt and flour, mix until completely combined and there are no lumps. Scrape down the sides of the bowl with a spatula.
With the mixer on low, add the eggs, one at a time, and beat until just mixed through, do not to over-beat. Scrape down the sides of the bowl with a spatula.
Add sour cream, cream and vanilla extract and beat until mixed through.
Pour HALF of the batter on top of the brownie layer in the prepared pan. Level the top with a spatula and arrange a layer of Peanut Butter Cups.
Add the rest of the cheesecake batter. Level the top with a spatula.
Set the springform pan in a large roasting pan, that is deep enough to add water to it. Pour HOT water into the roasting pan, about halfway up the sides of the springform pan.
Transfer the cheesecake to the preheated oven and bake it for 45-50 minutes. Or until the cheesecake is just slightly wobbly in the center, but puffy and settled on the sides.
Turn off the oven and crack open the door. Cool cheesecake completely in the open oven.
Once completely cooled remove from the oven and refrigerate for at least 5-6 hours.
Run a butter knife around the edges to release it from the pan. Store in the fridge until ready to serve.