Ingredients
Units
Scale
For the cookie cake:
- 1/2 cup unsalted butter, room temp
- 3/4 cup granulated sugar
- 1 egg, room temp
- 1 tbsp clear vanilla extract
- 1 1/4 cup all purpose flour
- 3/4 tsp kosher salt
- 1/2 tsp cornstarch
- 1/2 tsp baking soda
- 1/3 cup + 1 handful rainbow sprinkles, divided
- 1/2 cup white chocolate chips
For the vanilla buttercream:
- 1 cup unsalted butter, cold
- 3 cups powdered sugar, sifted
- 1/2 tsp vanilla extract
- pinch salt
- 1 tbsp heavy cream
Instructions
- Make your cookie cake. Preheat your oven to 350 degrees F and prepare a 9-inch round pan (I used a springform pan, but a properly-lined cake pan will work too) by greasing and lining with parchment paper. I like to cut a circle slightly larger than the pan diameter so that there is extra parchment going up the sides of the cookie cake.
- In a large mixing bowl, cream together you butter and sugars on medium-high for 3-5 minutes until fluffy. Add the egg and clear vanilla and continue to beat on medium-high for 5 minutes, until the mixture becomes fluffier and lightened in color.
- In a separate mixing bowl, whisk together flour, cornstarch, baking soda, and salt. Add the dry ingredients to the egg/sugar/butter mixture and mix on the lowest speed (or by hand) until streaks of flour *almost* disappear. Add your white chocolate chips and 1/3 cups sprinkles, mixing on low until just distributed.
- Scoop cookie batter into your prepared 9 inch pan and smooth the top into an even layer with an offset spatula. Sprinkle with remaining handful of sprinkles to garnish.
- Bake cookie cake at 350 degrees F for 20-25 minutes, until golden brown and edges appear set. Allow to cool completely to room temperature in its pan, then carefully lift onto your serving plate.
- Make your vanilla buttercream. Beat cold butter in a large mixing bowl at medium-high speed for 5 minutes, until lightened in color and shiny. Reduce mixer speed to low and add powdered sugar 1 cup at a time until fully incorporated.
- Increase mixer speed to medium and add vanilla, salt, and heavy cream. Increase to medium high and beat until the frosting is almost white and whipped. Add food coloring gel to your preference (I did 2 squeezes rose and 1 squeezes violet for this purple buttercream). Remove from the mixer and using a spatula, mix buttercream to remove air bubbles until it is smooth in texture.
- Pipe buttercream around your cake in whatever style you choose! I love to write a little message in the middle of my cookie cakes.
- Enjoy your cake at room temp! After a few hours, store in the fridge in an airtight container (like a cake box). Refrigerated frosted cookie cake is good for up to 4-5 days.
Notes
- Clear vanilla is the key to birthday cake confetti flavor! Regular vanilla extract will yield a more chocolate chip-like cookie flavor.
- This vanilla buttercream recipe is adapted from Courtney Rich’s recipe, which is the recipe I use for all vanilla buttercream! It’s the best.
- Category: cake, cookies