1. Prepare the Pan:

• Lightly grease the sides and bottom of a 9-inch round springform pan with cooking spray. Set aside.

2. Make the Mousse:

• In a stand mixer, whip the heavy cream on high speed until soft peaks form (about 4-5 minutes).
• Add the confectioners’ sugar and dry cake mix powder, then whip until stiff peaks form (about 2 minutes). Fold in the rainbow sprinkles and set the mixture aside.

3. Combine with Cream Cheese:

• In the same mixer bowl, beat the cream cheese, granulated sugar, and vanilla extract until smooth (about 1 minute).
• Gently fold the whipped cream mixture into the cream cheese mixture until fully combined and fluffy.

4. Layer the Cake:

• Spread about 1/4 cup of the mousse mixture onto the bottom of the prepared pan to help the first layer of Oreos stick.
• Dip each Oreo briefly into the milk, then layer them across the bottom of the pan, breaking cookies as needed to fit.
• Spread 1/3 of the mousse mixture evenly over the Oreos using an offset spatula.
• Repeat the Oreo and mousse layers two more times, finishing with the remaining mousse on top.

5. Chill and Garnish:

• Cover the cake and refrigerate for at least 4-6 hours, or preferably overnight, to allow the flavors to meld and the cake to set.
• Just before serving, garnish with additional whipped cream and rainbow sprinkles for an extra festive touch.