Nothing says summer like ice cream! Instead of a sundae, serve this ice cream pie for dessert. You can use whatever flavor of ice cream you want and even add your favorite sundae toppings, too!
For the crust: Adjust oven rack to middle position and heat oven to 325 degrees. Spray 9-inch pie plate with vegetable oil spray.
Add 16 Oreo cookies (broken into large pieces) to food processor and lock lid into place. Hold down pulse button for 1 second, then release. Repeat until cookies are coarsely ground, about fifteen 1-second pulses.
Turn on processor and process until crumbs are uniformly fine, about 15 seconds. Stop processor and remove lid. Add melted butter to processor and lock lid back into place. Turn on processor and process until mixture resembles wet sand, about 15 seconds.
Stop processor, remove lid, and carefully remove processor blade (ask an adult for help). Use rubber spatula to scrape mixture into greased pie plate. Use your hands to press crumbs into even layer covering bottom and sides of pie plate.
Use oven mitts to remove pie plate from oven (ask an adult for help). Place pie plate on cooling rack and let crust cool completely, about 30 minutes.
For the filling: Remove ice cream from freezer and let soften on counter for 10 to 15 minutes. In large bowl, combine softened ice cream and remaining 8 Oreo cookies (broken into large pieces). Use back of large spoon to mash until well combined.
Use rubber spatula to transfer ice cream mixture to cooled crust and smooth top. Cover pie with plastic wrap and freeze until filling is completely frozen, at least 3 hours or up to 1 week.
Slice pie into wedges. Dollop each piece of pie with Whipped Cream (if using). Serve.