Line a 9 inch springform pan with plastic wrap. Place in the freezer while preparing the cookie layer.

Preheat oven to 350°F and line a baking sheet with parchment paper.

Add 25 crushed Oreo cookies to a small bowl.

Stir in melted and cooled butter until crumbs are coated.

Evenly spread cookie crumbs on baking sheet and bake for 7-8 minutes, then cool.

Remove both chocolate and cookies and cream ice cream from freezer to thaw slightly.

Spread ½ quart of chocolate ice cream into the bottom of the pan, then freeze for 30 minutes.

Microwave hot fudge until softened, then spread over the ice cream layer.

Sprinkle baked cookie bits over hot fudge and freeze for 1 hour.

Spread cookies and cream ice cream over the layered cookie crunch, then freeze for 4-6 hours or overnight.

Prepare whipped cream by beating heavy cream, powdered sugar, and vanilla until stiff peaks form.

Frost the top and sides of the cake with whipped cream.

Decorate with additional Oreo cookies and drizzle with chocolate syrup if desired.