1 gallon vanilla ice cream
1 gallon chocolate ice cream
15 chocolate sandwich cookies, such as Oreos
1 9-inch round cake, such as 1/4 recipe of Buddy Valastros Chocolate Cake or a boxed cake mix
Whipped cream, for garnish
Remove ice cream from freezer to let it soften a little.
Place cookies in a large resalable plastic bag. With a rolling pin, smash the cookies until they form a coarse crumble.
In the bottom of a 9-inch spring form pan, spread all of the vanilla ice cream. Sprinkle half of the cookie crumbs on top of the ice cream. Top that with chocolate ice cream, spread to cover the cookies and place back into the freezer to harden for about an hour.
To assemble the cake, with a serrated knife, cut through the chocolate cake so that you have two thin rounds of chocolate cake. Place the bottom of the cake onto a cake plate. Remove ice cream from the spring form pan and place the ice cream on top of the bottom layer of cake. Place the other round of cake on top to make a giant ice cream sandwich.
With a piping bag, pipe whipped cream onto the cake. Flatten it out with a large off-set, metal spatula.
Decorate with the rest of the cookie crumbs.