In a food processor or blender, pulse 30 Oreos (including the cream filling) into a fine crumb. You should have about 3 cups crumbs, or 330g. Pour crumbs into a large bowl. Add the melted butter and stir to combine. The mixture will be thick and quite wet. Try to smash/break up any large chunks. Pour the mixture into an ungreased 9×13-inch pan. With medium pressure using your hand, pat the crumbs down into the bottom to make a compact, thick crust. Freeze for 15 minutes.

During that time, place the softened chocolate ice cream in a bowl and give it a good stir to rid any frozen lumps. You want a nice smooth, soft ice cream. Spread it on top of the frozen crust. Freeze for 15–30 minutes. (Closer to 30 minutes is ideal.)

During that time, place the 2nd ice cream flavor into a bowl and stir it until it is smooth and very soft. Carefully spread on top of the chocolate ice cream. Freeze for 15–30 minutes. (Closer to 30 minutes is ideal.)

Make sure the hot fudge is spreadable consistency. You may have to slightly heat it if using store-bought. Spread it on top of the ice cream as best you can. Because it is not as cold as the ice cream layer, the two will slightly mix together as you spread. That’s ok. Freeze for 15–30 minutes. (Closer to 30 minutes is ideal.)

Using a hand mixer or a stand mixer fitted with a whisk attachment, beat the heavy cream, confectioners’ sugar, and vanilla on medium-high speed until stiff peaks form, about 4–5 minutes. Spread on top of hot fudge layer, then top with sprinkles. Cover with aluminum foil and freeze for at least 12 hours before serving (and up to a few days).

Use a very sharp knife to cut, making sure you are cutting into the crust. Keep leftovers in the freezer.