Roughly crush 14 Oreos in a sealed bag with a rolling pin, leaving some larger pieces, then set them aside for topping.
Pulse the remaining Oreos into fine crumbs in a food processor, mix with the melted butter, and press firmly into the base of a 9-inch springform pan. Chill while you make the filling.
Beat the softened cream cheese until smooth, scraping down the bowl, then mix in the sugar and vanilla until fully blended.
Fold in the whipped topping along with most of the chopped Oreos, then spread the mixture evenly over the chilled crust. Cover and refrigerate for at least 4 hours, until set.
Just before serving, scatter the remaining chopped Oreos on top, slice, and enjoy.
Notes
Let cream cheese soften fully before beating to avoid a lumpy filling.
Fold in the Oreo pieces gently to keep the filling from turning gray.
Press the crust firmly and chill it before adding the filling so it holds together when sliced.
Chill at least 4 hours, ideally overnight, for the cleanest slices.
Add the top layer of Oreos just before serving so they stay crunchy.
Freezes well without the topping for up to a month; thaw overnight before serving.