Have ready a 10 - 11 inch tart pan with removable bottom or 10 inch pie pan.
Be sure your cookies are crispy before trying to crush them into crumbs. If fresh baked, take several cookies at a time and place them in the freezer for 5-10 minutes (unwrapped). This will harden and dry them, making them easier to crush into crumbs.
To make the crust, process in a food processor or use a gallon size zip-top bag (freezer bags are stronger) and fill it with approximately 2 1/2 - 3 cups of chocolate chip cookies. Remove the air from the bag and seal, then begin rolling over the cookies with a rolling pin, crushing the cookies to a very small crumb size -- if the cookies aren't crushed quite finely, the crust will fall apart when cut.
(To make the crumbs even more chocolately, add some extra chocolate chips to the food processor -- the top layer of crumbs shown has chocolate chips added.)
Once uniformly crushed, measure out to be sure you have enough crumbs – repeat if you need more crumbs. Note: this step is even easier using a food processor instead! If you want your crust to be extra chocolatey, add 1/3 cup chocolate chips to the food processor and process with cookies (as pictured in the top portion of the prepared crumbs).
Pour the crumbs into a medium-sized bowl and stir in the slightly cooled, melted butter or Buttery Sticks, stirring with a fork until the crumbs begin to stick together when pressed. It is important that the mixture not be too wet, so if the crumbs are very wet at this point, crush more cookies to add to the mixture. The consistency is right when you can press the mixture between your fingers and it sticks together but is not at all drippy with butter.
Transfer the crumb-butter mixture into a pie pan and press with your fingers to create an even thickness along the bottom and sides of the pan. If using a tart pan with removable bottom, you may find it easier to place the pan on a cookie sheet so the crust bottom is not disturbed during transfer.
Refrigerate the crust for 20 - 30 minutes to help it set. Preheat oven to 350° F (static) or 325° F (convection).
Bake crust for 10 minutes or until firm. Remove to cool completely in the refrigerator or at room temperature before filling.