Place the chocolate sandwich cookies in the bowl of a food processor and pulse until the cookies become fine crumbs. Mix in the melted butter until all the crumbs are moistened. Press the crumbs into the bottom and up 1 inch of the sides of a 9-inch spring form pan, making sure it evenly coats the bottom of the pan.
Freeze the crust for 5-10 minutes while the ice cream sits out at room temperature to soften.
When the ice cream has softened, scoop it onto the crust and use a wooden spoon or off-set spatula to spread it evenly over the bottom. Freeze for 30 minutes.
When the ice cream has re-frozen, prepare the ganache by adding the chocolate chips and heavy cream to a microwave-safe bowl. Melt at 50% power for 60 seconds. Stir the chocolate really well, then heat again at 50% power for 30 seconds. Continue to heat at 50% power for 15 seconds (stirring after each time) until the chocolate is melted.
Pour the ganache evenly over the frozen ice cream base and spread evenly over the top. Freeze at least 10 minutes or until ready to serve (overnight is best, when possible).
Before serving, let the pie sit at room temperature for about 10 minutes (or until soft enough to cut) before serving.
Notes
Most "half gallon" ice cream containers are now only 1½ quarts. You can also use 3 pints of ice cream.
This pie will stay fresh up to 3 months. Be sure to keep leftovers tightly wrapped to prevent freezer burn. The best way to do this is to slice and wrap individual pieces in plastic wrap or foil and store in a freezer bag.