1. In a food processor, combine cookies, peanut butter and melted butter and process until smooth and combined. Press into the bottom of a 9″ Springform pan, top with a single layer of chopped large peanut butter cups and set aside.
1. In a small bowl, stir together chocolate chips and oil. Microwave on high in 30 second intervals, stirring each time. Set aside to cool slightly. In a large bowl, beat cream cheese with an electric mixer until smooth. Add icing sugar, melted chocolate, and peanut butter and beat on medium speed until smooth, scraping down the sides as necessary.
2. In a separate bowl, beat cream with an electric mixer on high speed until stiff peaks form. Gently fold whipped cream into cream cheese mixture, being careful not to deflate the whipped cream. Spread cheesecake mixture over crust and smooth the top. Cover with plastic wrap and refrigerate for at least 8 hours or overnight.
1. Before serving, beat 1 cup whipping cream and 3 tablespoons icing sugar with an electric mixer on medium-high speed until stiff peaks form. Spread over the top of the cheesecake or pipe into swirls. Decorate with chopped mini peanut butter cups as desired.