Preheat your oven to 350°F (175°C). In a medium bowl, combine the finely crushed Oreo cookies (1) with the melted butter (2). Mix until well combined and the crumbs resemble wet sand.

Press the mixture evenly into the bottom of a 9-inch springform pan. Bake the crust for 8-10 minutes. Remove from the oven, let cool, and reduce oven temperature to 325°F (160°C).

In a large mixing bowl, beat the softened cream cheese (4) on medium speed until smooth and creamy. Add the granulated sugar (5) and beat until well combined and fluffy.

Add the creamy peanut butter (6) and mix until fully incorporated and smooth. Pour in the heavy cream (7), vanilla extract (9), and salt (10). Mix on low speed until just combined.

Add the eggs (8) one at a time, mixing on low speed after each addition until just incorporated. Gently fold in the chopped mini Reese's peanut butter cups (11).

Wrap the bottom of your springform pan tightly with foil (for a water bath, if using). Pour the cheesecake batter over the cooled Oreo crust.

If using a water bath, place the foil-wrapped pan into a larger roasting pan and pour hot water halfway up the sides. Bake for 60-75 minutes, or until edges are set and center slightly jiggles.

Turn off the oven, crack the door, and let the cheesecake cool in the oven for 1 hour. Remove, cool completely on a wire rack, then cover and refrigerate for at least 6 hours, or overnight.

For the ganache: In a microwave-safe bowl, combine chocolate chips (13), heavy cream (14), and butter (15). Microwave in 30-second intervals, stirring, until smooth and glossy. Let cool for 10-15 minutes.

Once cheesecake is chilled, remove springform sides. Pour ganache over the top, spreading evenly. Garnish with halved full-size Reese's (17), mini Reese's (18), and chopped peanuts (19) as desired. Refrigerate for another 30 minutes to set ganache.

Slice with a sharp knife (wiping clean between slices) and serve chilled. Enjoy!