To make the crust:
Pulse Oreo cookies, with filling, in a food processor until finely ground. Transfer crumbs to a medium bowl, add melted butter, and mix until combined and moistened. Press the mixture onto the bottom and up the sides of a 9-inch (23cm) tart pan
. Place it in the fridge for 30 minutes to firm up before adding the filling (or before baking the crust). If possible, I recommend to bake the crust in a 350F/180C preheated oven for 5-6 minutes, then let it cool completely on a wire rack before adding the filling. This will make the crust more crisp and less soft.