Preparation

• Prepare the crust: Line a 9-inch springform pan or deep cake pan with parchment paper. In a bowl, combine the crushed chocolate sandwich cookies with the melted butter, mixing until evenly coated. Press the mixture firmly into the bottom of the pan to create an even crust layer. Place the pan in the freezer for 15 minutes to set the crust.
• Add chocolate ice cream layer: Spread the softened chocolate ice cream evenly over the chilled crust, smoothing the surface with a spatula. Freeze the pan for 30 minutes to let this layer firm up.
• Apply fudge layer: Warm the hot fudge sauce slightly to make it spreadable, then carefully pour and spread it over the chocolate ice cream layer in an even layer. Return the pan to the freezer for 15 minutes to set the fudge.
• Add vanilla ice cream layer: Spread the softened vanilla ice cream over the fudge layer, smoothing it evenly with a spatula. Cover the cake tightly with plastic wrap and freeze for at least 4 hours or overnight, until completely firm.
• Finish and serve: Before serving, remove the cake from the pan and spread whipped topping or homemade whipped cream evenly over the top and sides. Garnish with chocolate shavings, sprinkles, or optional crushed cookies or chopped candy pieces. Slice with a knife dipped in warm water, wiping between cuts for clean slices. Serve immediately.