In a food processor, mix oreos until completely pulverized. To prevent any large crumbs from making their way into the crust, sift the powdered crumbs through a sieve. Pour the crumbs into a bowl and stir in melted butter.
Firmly press the crust mixture into a large springform pan, creating an even and compacted surface. Set aside.
In a standing mixer, cream cream cheese and sugar on medium speed until light and fluffy, about 3 minutes. Turn the mixer to low and add in the eggs one at a time. Add in the peanut butter and vanilla extract, mixing until light and fluffy.
Pour cheesecake mixture into prepared pan, smoothing to even the surface. Wrap the pan in tin foil and place in a water bath, then place the entire thing into the oven.
Bake for 1 hour and 30 minutes, then remove from oven and allow to cool completely in fridge before glazing.
To make the ganache, heat the milk in a small saucepan over low heat until scalding. Remove from heat and stir in chocolate chips. Pour almost all of the glaze over chilled cheesecake, then top with peanut butter cups, and drizzle with remaining glaze!