Remove the chocolate ice cream 10-15 minutes before ready to use to thaw.
Place several sheets of plastic wrap in a 9 inch springform pan to fully cover the inside, leaving the edges hanging off.
Spread the thawed chocolate ice cream into the bottom of the springform pan. Use a frosting knife or spatula to smooth out the ice cream.
Place the pan back into the freezer for one hour.
Warm the hot fudge for 20-30 seconds in the microwave to allow it to easily spread.
Remove the pan from the freezer and pour the warm fudge over the top and spread evenly with your frosting knife or spatula.
Sprinkle the crumbled Oreos on top of the fudge layer and return the pan to the freezer for one hour.
Remove the vanilla ice cream 10-15 minutes before ready to use to thaw.
Spread the thawed vanilla ice cream over the top of the Oreo layer.
Return the cake to the freezer for 5-6 hours or overnight to fully set.
When you are ready to decorate the cake, remove the cake from the freezer while you prepare your frosting.
Whip the cold cream, powdered sugar and vanilla extract with an electric mixer on medium for one minute and then switch to high speed until stiff peaks form.
Unhinge your springform pan and use the edges of the plastic wrap to lift the ice cream cake from the pan. Place the cake onto your serving platter. (Note: I recommend chilling your serving platter for 10-15 minutes before transferring to prevent the base of the cake from melting quickly).
Working quickly, evenly spread the whipped cream mixture across the top and sides of the cake. Use your spatula, frosting knife or pastry cutter to smooth out the whipped cream frosting.
Garnish the top of the cake with sprinkles and pipe on vanilla frosting or extra whipped cream for decoration if desired.
Slice and serve immediately or return the cake to the refrigerator until ready to serve.