Pulse 24 Oreo cookies in a food processor until they form fine crumbs, about 30 seconds. Drizzle in melted butter and pulse until the mixture looks like wet sand, about 5 pulses. Press firmly and evenly into the bottom of a 9-inch springform pan, using the bottom of a measuring cup to compact it. Freeze for 15 minutes to set.

Spread softened vanilla ice cream evenly over the chilled crust, working quickly with a rubber spatula to create a smooth layer about 1 inch thick. Scatter half the chopped Oreos over the surface and press them in gently. Freeze for 30 minutes until firm.

Drizzle warm fudge sauce over the frozen vanilla layer, spreading thinly with the back of a spoon. Working quickly, spread softened chocolate ice cream on top and smooth the surface. Scatter remaining chopped Oreos and press in lightly. Cover tightly with plastic wrap and freeze for at least 4 hours, preferably overnight, until completely solid.

Beat cold heavy cream, powdered sugar, and vanilla extract in a large bowl with an electric mixer on medium-high speed until stiff peaks form, about 2 to 3 minutes. Be careful not to overbeat. Spread or pipe the whipped cream over the top of the cake.

Sprinkle crushed Oreos over the whipped cream. Run a thin knife around the edge of the pan, then release the springform. Let sit at room temperature for 5 to 10 minutes before slicing with a warm, clean knife for clean cuts. Serve immediately.