Preheat oven to 350 degrees F. Line two large rimmed baking sheets with a silicone baking mat.
In the bowl of an electric stand mixer fitted with the paddle attachment cream together the butter and granulated sugar until light and fluffy, 3-4 minutes. Scrape down the sides of the bowl as needed.
Add the egg and vanilla and mix again for 1-2 minutes until the batter lightens in color. Scrape the sides of the bowl as needed.
In another bowl, whisk together the flour, baking powder, baking soda, and salt.
Add the dry ingredients to the wet ingredients and mix until well combined.
By hand, gently stir in the sprinkles.
Scoop the cookie dough into rounded ball, I use my #24 cookie scoop, and place on the prepared baking sheets about 3 inches apart.
Bake for 11-13 minutes until slightly crackly on top. Allow to cool on baking sheet 3 - 5 minutes to set.
Removing to a cooling rack to cool completely. Once completely cool, assemble ice cream sandwiches.