Preheat the oven to 350 degrees.
Use a food processor to finely crush 20 Oreo's (no need to remove the frosting filling before crushing them). You can also place the cookies in a gallon bag and use a rolling pin to crush them if you do not have a food processor.
Pour the crushed Oreo's into a medium-sized mixing bowl and add the melted butter. Stir until the mixture is completely coated.
Using your fingertips or the back of a measuring cup, press the mixture down evenly throughout a standard 9-inch pie plate.
Bake the crust for 8-10 minutes, then remove it from the oven and allow it to cool to room temperature before adding the pie filling.