Lay graham crackers in a single layer across the bottom of a 9 x 13 baking dish, breaking apart as necessary.
Spread half of the hot fudge sauce on top of the graham crackers. Set aside.
Using a stand mixer or hand mixer, whip heavy cream until stiff peaks form. Set aside.
In a separate bowl, beat cream cheese for 2 to 3 minutes on medium-high speed until light and fluffy. Add peanut butter and beat until combined.
Add powdered sugar and beat until no lumps remain. Beat in vanilla extract.
Fold in whipped cream. Fold in chopped Reese's.
Spread half of cheesecake mixture on top of hot fudge sauce.
Add a layer of graham crackers, remaining half of hot fudge sauce, and remaining cheesecake mixture. Top with another layer of graham crackers.
Using a stand mixer or hand mixer, whip heavy whipping cream, powdered sugar, and vanilla extract until stiff peaks form.
Spread whipped cream on top of graham crackers.
Combine graham cracker crumbs, melted butter, and sugar in a small bowl. Mix to combine. Sprinkle over the top of the cake.
Cover and chill for at least 8 hours.
Top with additional Reese's candy before serving, if desired.
