In the bowl of your electric mixer, add the whipping cream, powdered sugar and peanut butter. Using the whisk attachment, beat on high speed until stiff peaks form, usually 2-3 minutes.
Spoon 3/4 of a teaspoon of whipping cream on a cookie, press another cookie on top and continue until your cakes are 5 cookies tall.
Garnish top of cake with a dollop of cream and peanut butter cup candy if desired.
Place onto your serving tray and refrigerate overnight. The cakes soften and may be difficult to move the next day before serving.