Line the bottom and sides of an 8-inch springform pan with parchment paper and chill in the freezer for 15 minutes.
Spread the softened chocolate ice cream evenly into the bottom of the pan. Freeze for 30 minutes.
Pulse the cookies in a food processor until coarse. Toss with the magic shell coating until fully saturated.
Spread the fudge sauce over the chocolate ice cream layer, leaving a small border. Press the coated cookie crumbs firmly into the fudge. Freeze for 45 minutes.
Spread the softened vanilla ice cream carefully over the frozen crumb layer. Freeze the entire cake for at least 4 hours or overnight.
Remove from the springform pan, frost the outside with whipped topping, and pipe decorative borders. Freeze for 1 hour before slicing.