No-Bake Funfetti Oreo Icebox Cake

Ingredients

For the Birthday Cake Mousse:
1¾ cups heavy whipping cream, very cold
½ cup powdered sugar, sifted
¾ cup dry white cake mix powder
8 ounces full-fat cream cheese, softened to room temperature
⅔ cup granulated sugar
2 teaspoons pure vanilla extract
¾ cup rainbow sprinkles, plus extra for garnish
For the Cookie Layers:
2 standard packages (about 36 cookies) birthday cake-flavored Oreo cookies
⅔ cup whole milk
For Garnish (Optional):
Additional whipped cream, for piping
Extra rainbow sprinkles

Instructions

Step 1: Prepare the Pan
Lightly grease the bottom and sides of a 9-inch round springform pan with non-stick cooking spray. This will help the cake release cleanly. Set the pan aside.

Step 2: Make the Whipped Cream Base
In the bowl of a stand mixer fitted with the whisk attachment, or in a large bowl using a hand mixer, beat the cold heavy whipping cream on high speed until soft peaks begin to form, about 4 to 5 minutes. Gradually add the sifted powdered sugar and the dry cake mix powder. Continue beating on high speed until the mixture forms stiff, firm peaks, about 2 minutes longer. Gently fold in ¾ cup of the rainbow sprinkles using a rubber spatula until they are evenly distributed. Transfer this whipped cream mixture to a separate bowl and set aside.

Step 3: Prepare the Cream Cheese Base
In the now-empty mixer bowl (no need to wash it), beat the softened cream cheese, granulated sugar, and vanilla extract together on medium speed until the mixture is completely smooth, creamy, and free of lumps, about 1 minute. Scrape down the sides of the bowl as needed.

Step 4: Combine the Mousse Components
Add the reserved whipped cream mixture back into the bowl with the cream cheese mixture. Using the spatula, gently fold the two components together until they are fully incorporated and a uniform, fluffy mousse forms. Be careful not to overmix, which could deflate the mousse.

Step 5: Assemble the First Layer
Spread about ¼ cup of the finished mousse onto the bottom of the prepared springform pan, smoothing it into an even layer. This thin base helps the first layer of cookies adhere.

Step 6: Build the Cookie and Mousse Layers
One at a time, dip each Oreo cookie into the milk for a quick second, ensuring it is moistened but not soggy. Arrange the dipped cookies in a single layer over the mousse in the pan, breaking a few cookies as needed to fill any gaps. Spread approximately one-third of the remaining mousse evenly over this cookie layer. Repeat the process with another layer of dipped cookies, followed by another one-third of the mousse. Add a final layer of dipped cookies, and then top with the remaining mousse, smoothing the top with an offset spatula.

Step 7: Chill and Set
Cover the springform pan tightly with plastic wrap. Refrigerate the assembled cake for at least 4 to 6 hours, or preferably overnight. This chilling time is essential for the cookies to soften to a cake-like texture and for the mousse to set properly.

Step 8: Decorate and Serve
Just before serving, carefully remove the sides of the springform pan. Transfer the chilled cake to a serving plate. For a beautiful finish, pipe additional whipped cream around the edges and generously sprinkle with extra rainbow sprinkles. Slice and serve chilled.