Step 1

Preheat the oven to 350° F and add a roasting pan or another large pan in the lower section of the oven to make a hot water bath. Place enough hot water in the pan that it will rise to 1-2 inches around the cheesecake springform pan.

Step 2

Line the bottom of a 9-inch springform pan with parchment paper cut into a circle to fit the inside bottom of the pan. Put parchment paper around the edges as well. Spray the pan with non-stick spray and set aside.

Step 3

In a medium size mixing bowl, stir together the brownie mix, oil, water, and egg, just until the ingredients are combined. Pour batter into the prepared springform pan. Bake for 35 minutes.

Step 4

Remove the pan from the oven and immediately sprinkle the chocolate and peanut butter chips onto the top of the hot brownie in an even layer. Allow the brownie crust to cool on the counter while preparing the cheesecake filling.

Step 5

Using 18-inch heavy-duty aluminum foil, wrap the outside of your springform pan with 3 layers of foil to ensure no water leaks into the cheesecake as it bakes in the water bath.

Step 6

Reduce the oven temperature to 325° F.

Step 7

In a large mixing bowl on medium speed, cream together the softened cream cheese until smooth.

Step 8

Add the sugar and vanilla extract and continue to mix on medium-high speed for another 1-2 minutes, scraping the sides of the bowl when needed, until the mixture is smooth.

Step 9

Reduce the speed to low and add the eggs, one at a time, scraping the bowl and mixing well after each egg. Do not overmix.

Step 10

With the mixer on low, add the creamy peanut butter and the heavy cream. If you prefer a more solid filling, add in cornstarch now. Mix until everything is thoroughly blended.

Step 11

Fold in the chopped peanut butter cups. Spoon the cheesecake batter on top of the brownie layer.

Step 12

Carefully place the wrapped springform pan in the hot water bath in the oven. Bake the cheesecake for 1 hour. The cheesecake is done when the top is light golden brown, and the center barely jiggles.

Step 13

When the cheesecake has cooked for an hour, turn off the oven and crack the oven door open about an inch by placing a wooden spoon in the door. Allow the cheesecake to cool in the oven for 30 minutes.

Step 14

Remove the cheesecake from the water bath, transfer it to a wire rack, remove the foil, and let cool for an hour.

Step 15

Place the cheesecake in the refrigerator to cool for at least 6 hours or overnight.

Step 16

After the cheesecake has chilled, gently run a knife along the sides, gently release the sides of the springform pan, and remove it from the cheesecake.

Step 17

Using a small heat-safe bowl, combine the chocolate chips and heavy cream. Heat in the microwave for 30-second bursts, stirring after each interval, until the chocolate is smooth.

Step 18

Pour the ganache slowly on top of the chilled cheesecake and gently smooth it over the top.

Step 19

Evenly sprinkle the top of the ganache-covered cheesecake with the chopped Reese’s Peanut Butter Cup candies. Enjoy!