Preheat your oven to 350 degrees and prepare a 9” springform pan by spraying with non-stick spray and set aside. (For added protection, you can add a round of parchment paper along the bottom of the springform as well)

In the bowl of a stand mixer equipped with a whisk attachment, add the brownie mix, vegetable oil, water, and egg and mix on high speed until smooth.

Pour into the bottom of the springform pan and smooth evenly.

Bake for 35 minutes.

Remove the springform from the oven and immediately add the semi-sweet and peanut butter chips to the top of the brownie. Try to space them out as evenly as you can.

Set aside.

To prepare the cheesecake filling, add the softened cream cheese and peanut butter into the bowl of a stand mixer equipped with a paddle attachment. Cream for 5-6 minutes or until light and fluffy. Scrape the sides and bottom of the bowl.

With the mixer on low speed, slowly add the sugar and flour. Once the sugar is combined, increase to medium speed, and mix for an additional 1-2 minutes.

Add the vanilla extract and mix until just combined.

Reduce the mixer to low speed and add the eggs one at a time until fully incorporated. Be careful not to overmix after adding the eggs!

Fold in the mini Reese Cup pieces last.

Pour the batter over the brownie layer and smooth. Gently tap to release any air bubbles.

Bake at 350 for 15 minutes then, without opening the oven door, reduce the heat to 200 and bake for an additional 55-60 minutes until the center slightly jiggles and the edges are set. (You are looking for a Jell-o consistency, not a runny/watery consistency. If the center still looks too watery, bake for an additional 5-10 minutes checking often. However, the cheesecake will set up more while cooling, so keep that in mind.)

Turn off the oven and slightly crack the oven door to allow the cheesecake to cool for 15-20 minutes before removing.

Allow cooling on a wire rack until completely cooled and place in the refrigerator for at least 6 hours but overnight is recommended.

Add the semi-sweet chocolate and the heavy cream into a microwave-safe bowl and heat on 30-second increments, stirring in between, until smooth.

Allow the chocolate to cool for 2-3 minutes, then pour over the chilled cheesecake and use an offset spatula to smooth the chocolate.

Top with the quartered mini Reese’s cups and serve!

Keep leftovers in an airtight container in the refrigerator for up to three days.