Preparation

• Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
• Chop the 15 Oreo cookies into chickpea-sized pieces and toss them with 3 tablespoons of melted unsalted butter. Spread the mixture on the prepared baking sheet.
• Bake the cookie mixture until it’s fragrant and crisp, about 5 to 8 minutes. Allow it to cool slightly before proceeding.
• In a medium heatproof bowl, microwave 1/2 cup of semisweet chocolate chips in 30-second increments, stirring well in between until melted and smooth, which will take about 60 to 90 seconds in total. Stir in 1 tablespoon of refined coconut oil.
• Add the baked cookie crumbs to the chocolate mixture, tossing to coat evenly. Spread this onto another parchment-lined sheet and refrigerate until hardened, about 30 minutes.
• While the crunch layer hardens, line a 9" springform pan with plastic wrap. Stir the 1 1/2 quarts of vanilla ice cream until smooth and spreadable, then evenly spread it in the bottom of the pan. Freeze for 30 minutes.
• Microwave the 11.5-oz. jar of hot fudge topping in 15-second increments until slightly warmed and spreadable, approximately 30 to 45 seconds total.
• Scatter the chilled chocolate crunch pieces over the frozen vanilla ice cream layer. Dollop and spread the fudge topping across the crunchies. Freeze the cake until slightly firm, about 15 to 30 minutes.
• Stir the 1 1/2 quarts of chocolate ice cream until smooth. Spoon it over the fudge layer and spread evenly. Cover the top with plastic wrap and freeze until firm, at least 4 hours or up to 1 week.
• About 2 hours before serving, carefully peel off the top plastic wrap. Invert the cake onto a serving platter, removing the sides of the springform pan and any remaining plastic wrap. Return the cake to the freezer.
• Beat 1 1/2 cups of heavy whipping cream, 1/4 cup of confectioners' sugar, and 1 1/2 teaspoons of pure vanilla extract with a handheld mixer on medium-high speed until stiff peaks form. Transfer one-third of the whipped cream to a piping bag fitted with a star tip.
• Spread the remaining whipped cream over the top and sides of the cake. Pipe a decorative shell border around the top edge and base of the cake if desired. Freeze the decorated cake, uncovered, for 1 to 2 hours before serving.
• Before serving, sprinkle the top edge and base of the cake with colorful sprinkles. Let it sit at room temperature for about 5 minutes, then slice and enjoy!