Instructions

• Process 24 Oreo cookies in a food processor until finely ground. Transfer crumbs to a medium bowl and stir in 5 tablespoons melted butter until evenly moistened. Press the mixture firmly and evenly into the bottom of a 9-inch springform pan. Refrigerate while you prepare the fillings.
• In a clean bowl, use an electric mixer to beat 1 1/4 cups heavy whipping cream to stiff peaks. Divide the whipped cream into two equal portions (one portion for the peanut butter layer, one portion for the chocolate layer). Leave both portions in separate bowls.
• In another bowl, beat 5 ounces softened cream cheese, 2 tablespoons softened butter, and 3/4 cup creamy peanut butter until smooth. Beat in 1 1/4 cups confectioners’ sugar until well combined and smooth.
• Gently fold one portion of the whipped cream into the peanut butter mixture until evenly incorporated and light. Spread this peanut butter mousse evenly over the chilled Oreo crust. Return the pan to the refrigerator while you make the chocolate mousse.
• Place 5 ounces chopped bittersweet chocolate and 3 1/2 ounces chopped milk chocolate in a heatproof bowl. In a small saucepan, bring 1/3 cup sugar and 1/4 cup milk to a boil, stirring to dissolve the sugar. As soon as it boils, pour the hot mixture over the chopped chocolate. Whisk until the chocolate is completely melted and the mixture is smooth. Stir in 1/2 teaspoon vanilla extract. Cool the mixture to room temperature, stirring occasionally.
• Gently fold the remaining portion of whipped cream into the cooled chocolate mixture until fully combined and airy. Pour the chocolate mousse over the peanut butter layer and smooth the top. Refrigerate (or freeze to speed up) until the mousse is firm.
• To make the ganache, place 6 ounces chopped semi-sweet chocolate in a small bowl. Bring 2/3 cup heavy whipping cream to a boil, then pour it over the chopped semi-sweet chocolate. Stir until smooth, then stir in the remaining 1/2 teaspoon vanilla extract. Cool the ganache until it is almost room temperature, stirring occasionally.
• Spread the cooled ganache evenly over the chilled cheesecake. Refrigerate the assembled cheesecake at least 1 hour before serving to allow the ganache to set.