Oreo Ice Cream Cake

Notes: This cake is prepared in layers, and needs to be frozen for awhile in between each layer. The finished cake is best if frozen overnight, or at least 4 hours.

1. Place all of the Oreo cookies in a large zippered storage bag. Seal the bag, getting out as much air as possible. Take a rolling pin and smash the cookies in the bag.
2. Reserve 1 cup of the crushed Oreos and set that aside. Place the remaining crushed Oreos into a large bowl.
3. Melt the butter by putting it into a microwave safe cup, and heating on 60% power for a minute (or more,) until the butter is just melted.
4. Pour the melted butter over the crushed Oreos in the bowl, and stir well to coat.
5. Spread the butter/crumb mixture into a 13 x 9 x 2 inch pan. Lay a sheet of waxed paper over the mixture, and press on the paper to compress the mixture evenly into a crust. Freeze the crust for 10 minutes.
6. Remove the ice cream from the carton, and set it on a cutting board. (For easiest assembly, use ice cream that comes packaged in a rectangular block-type carton that can easily be pulled apart from the ice cream.) Use a large, sharp knife to slice the ice cream into ½ inch slices.
7. Remove the crust from the freezer. Lay a single layer of ice cream slices over the Oreo crust, ensuring that the slices are as tight as possible, cutting the slices to fit, as necessary to cover the crust. Smooth the top of the ice cream with a knife.
8. Heat the caramel (or hot fudge) slightly until it is just pourable. Pour the caramel (or hot fudge) over the ice cream layer, spreading to the edges.
9. Freeze the cake for 30 minutes, or until the ice cream and topping are mostly set.
10. Use a handheld mixer to whip the heavy cream together with the powdered sugar until soft peaks form.
11. Spread the whipped cream evenly over the top layer of the cake, being sure to reach the edges of the pan.
12. Sprinkle the reserved Oreo crumbs over the whipped cream layer.
13. Cover and freeze the cake overnight, or until fully set.
14. To serve, remove cake from freezer and allow it to sit at room temperature for 5-10 minutes to soften. Dip a sharp knife into warm water, and wipe it dry. Cut the cake into serving pieces with the warmed knife. Re-warm the knife as needed.
15. Serve drizzled with additional caramel (or hot fudge,) if desired.