In a food processor blend your Oreo cookies (filling and all) into a fine crumb.
Place the crumbs into a large mixing bowl.
Add the sprinkles and melted butter.
Mix together until well combined.
Place the crust mixture into your tart or pie pan and press down into the bottom and sides to form crust.
Bake in the oven for 10 minutes at 350 degrees F.
Remove from oven and let cool.
Fill with desired non-baked fillings (like custards, puddings, cheesecake, etc).