To make the crust, crush the graham crackers using a food processor. (You could also crush them in a plastic bag with a rolling pin.) Mix the graham crackers with the melted butter and press the mixture into a 9 inch springform pan or 9 inch pie plate. Place the crust in the freezer to firm while you make the filling.
To make the filling, whip the whipping cream until light and fluffy, then beat in 2 teaspoons of sugar. Set aside. Add the cream cheese to a large bowl or the bowl of a stand mixer and beat until light and fluffy. Add the sugar, Reese’s spread, and vanilla, and mix until smooth. Using a spatula, fold in the whipped cream until combined. Add the Reese’s cups and fold in gently to distribute the candy throughout. Pour the filling mixture into the crust and spread evenly. Freeze 2+ hours or refrigerate 4+ hours, until firm.
When the cheesecake is firm, make the ganache topping by adding the chocolate chips to a heat-proof bowl. Heat the cream in a microwave safe bowl (I used a 2 cup measuring cup) until boiling, then pour over the chocolate chips. Let sit for a few minutes, then stir until the chocolate is melted and the ganache is smooth. Allow to cool for a few minutes, then pour over the cheesecake, using an offset spatula or a knife to smooth. Sprinkle the chopped Reese’s peanut butter cups on the top of the cheesecake. Return the cheesecake to the refrigerator or freezer for 30 minutes, or until the ganache has cooled and firmed.