Melt butter in small saucepan, cool slightly. While butter is melting, put cookies into food processor and pulse until finely ground. You can also use a gallon~size freezer bag and use a rolling pin or bottom of a pan and smash.
Reserve 1/4 cup of cookie crumbs for topping.
In medium bowl, place cookie crumbs and add melted butter and whisk until fully incorporated. Place into a 9×9 springform pan. Press lightly with fingers until the surface is smooth. Let cool in refrigerator for 15 minutes.
Cheesecake Filling
While the cookie crust is cooling, in a medium bowl, beat cream cheese, sugar and peanut butter and mix well. Add Cool Whip and beat lightly.
With a wooden spoon, pour dollops into prepared crust, smoothing out to the edges.
Sprinkle cookie crumbs on top and let refrigerate overnight, or at least 2-3 hours.