Weigh out the ingredients
You'll need flour, baking powder, baking soda, salt, butter, brown sugar, sugar, egg, vanilla, and sprinkles.
Cream butter & sugars
In the bowl of a stand mixer, beat the butter and sugars together until light & fluffy, about 2-3 minutes.
Add the egg and vanilla and beat until fully incorporated.
Add egg & vanilla
Scrape down the bowl, then add the dry ingredients and mix until just combined. Do not over-mix!
Add dry ingredients
Gently fold in the sprinkles.
Using a 2 tablespoon cookie scoop, portion the cookie dough and place on one baking sheet lined with parchment paper. Freeze the cookie dough for 30 minutes.
Portion & freeze cookie dough
Place the frozen cookie dough on one prepared baking sheet placed about two inches apart. Bake the cookies for about 10 minutes. Allow cookies to cool completely on the baking sheet.
Enjoy these soft birthday cake sugar cookies!