Place the egg in a bowl of warm water for 5 mins (to bring it to room temperature)

Preheat the oven to 350F then line a baking sheet with parchment paper and set it aside.

Cream the butter, granulated sugar, and powdered sugar together until smooth and creamy.

Remove the egg from the bowl of warm water, crack it and beat it and the vanilla extract until combined.

Add in the dry ingredients (flour, baking powder and salt) and mix until just combined.

Use a large cookie scoop and scoop out 8 equally sized cookie dough balls.

Roll the dough into balls and then roll the balls in the sprinkles.

Flatten the cookies to ¾ inch thickness

Bake for 12-13 min until lightly golden on the edges

Remove from the oven and let sit on the baking sheets for at least ten min before removing to a cooling rack to fully cool down.

Make the cake flavored buttercream

Using a hand or stand mixer, cream the butter until smooth.

Add powdered sugar, cake batter extract and heavy cream.

Beat for 2 mins on low speed and beat on HIGH for 4 mins creating a very light and fluffy buttercream.

Decorating

Add the frosting to a piping bag fitted with a Tip 10 or 12

Starting in the center of the cookie, pipe a dot and then make a tight circle around it. Continue this until the cookie is fully frosted. Immediately top with sprinkles.