Directions

1. Preheat the oven to 350°F. Spray two 8-inch round cake pans with cooking spray and coat with flour, tapping out any excess. Set aside.
2. Chop eight cookies and set aside.
3. In a large bowl, beat together the cake mix, eggs, milk, oil and 2 teaspoons vanilla, using a hand or stand mixer, until well combined. Mix in the chopped cookies.
4. Divide the batter between the prepared pans and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
5. Cool the cakes in the pans for 10 minutes before transferring to a wire rack to cool to room temperature.
6. In a food processor, process eight cookies into crumbs. Set aside.
7. In a large bowl, beat the butter on medium speed for 1 minute. Add the powdered sugar and beat for 1 minute until combined. Scrape down the sides of the bowl and add the remaining 2 teaspoons of vanilla and the heavy cream. Mix on medium-high speed for 3-4 minutes. Add the cookie crumbs and mix until combined.
8. Trim the rounded tops off the cake layers and slice each layer in half lengthwise to create a total of four cake layers. Using a 4-inch round cutter, cut a circle from the centers of two of the layers.
9. Place one uncut layer on a serving platter and spread with 1/3 cup of the buttercream. Top with a center-removed layer and spread with 1/4 cup of the buttercream. Repeat with the second center-removed layer. Add the sprinkles to the center of the cake, and top with the final cake layer. Frost the outside of the cake with the remaining buttercream and decorate with the remaining eight cookies.