Prepare the Pan
Line a 9-inch springform pan with parchment paper or plastic wrap to make unmolding easier.
First Ice Cream Layer
Spread the softened chocolate ice cream evenly in the bottom of the pan.
Place in the freezer for at least 30 minutes to firm up.
Make the Cookie Crunch
Crush cookies into fine crumbs (a food processor works best).
Mix with melted butter until combined.
Add Cookie & Fudge Layers
Spread the cookie crumb mixture evenly over the chocolate ice cream.
Drizzle and spread hot fudge sauce over the crumbs (work quickly so it doesn’t harden).
Freeze again for 30 minutes.
Second Ice Cream Layer
Spread the softened vanilla ice cream over the fudge layer.
Smooth the top with a spatula.
Freeze for at least 4 hours, or until completely firm.
Add the Whipped Topping
Remove cake from the pan and peel off the parchment or plastic wrap.
Frost the entire cake with whipped topping.
Decorate with chocolate syrup, sprinkles, or chocolate shavings if desired.
Final Freeze
Freeze for at least 1–2 hours before serving for the best texture.