Birthday cake cookies are soft and chewy sugar cookies packed with funfetti sprinkles and birthday cake flavor. You only need 10 ingredients, and no boxed cake mix is required!
Cream the softened butter, light brown sugar, and granulated sugar together for 3 minutes until light and fluffy.
Mix in the egg, egg yolk, almond extract, and vanilla extract until just combined.
Mix in the flour, salt, baking soda, and baking powder until almost combined and there are still some dry flour streaks. Then fold in the rainbow sprinkles until just combined.
Scoop the dough with a standard cookie scoop (two-tablespoons) onto a parchment-lined baking tray.
Fill a shallow bowl with the extra rainbow sprinkles. Roll each cookie dough ball between your hands then dip the top of the ball into the sprinkles so just the top is covered. Don't roll the whole thing in sprinkles, they will melt! Then, place them on a parchment-lined baking tray. Freeze the cookie dough balls for 3-4 hours minimum, overnight is best!
Then preheat the oven to 350 F/180 C. Bake the cookies spaced 2-3 inches apart on a parchment-lined baking tray for 9-11 minutes or until the very edges are just golden brown.
Let the tray cool on a wire cooling rack before removing them, then enjoy!
Notes
*Measure your dry ingredients properly. This is my #1 baking tip! Do not ever scoop a measuring cup into your flour, as this always leads to using too much flour. Instead, use the spoon-level method. This means fluffing the flour first, then spooning it into your measuring cup/spoon. For the BEST results, use a kitchen scale!*Notes on cookie sizes: If you prefer large cookies, use a 3 tablespoon cookie scoop and add 2-3 minutes to the bake time. You will have roughly 15 cookies.Notes on sprinkles: Do not use any colored sugar or nonpareils- the colors will bleed into the cookie dough! I recommend using jimmy sprinkles only.Storage: Keep leftover cookies in an airtight container at room temperature for 3-4 days. The frozen cookie dough balls can be stored in a container or freezer bag for up to three months and be baked straight from the freezer.