Place graham crackers and sugar into the bowl of a food processor and pulse into fine crumbs. Add the melted butter and process just until the crumbs are moistened and stick together when you press with your fingers.
Press into a 9" pie plate or springform pan using a spoon or measuring cup to compress crust down. Place in the freezer while you make the filling.
Store in the fridge covered, for up to 3 days.