Set mixer to low speed and gradually stir dry ingredients into butter mixture. Add ingredients and stir until well-incorporated.
Fold in chocolate chips and then sprinkles. Cover with clear wrap and chill in refrigerator for 30 minutes.
1 ½ cup semisweet chocolate chips, ⅓ cup sprinkles
Preheat oven to 350F (177C) and line a cookie sheet with parchment paper
Once dough has finished chilling, drop by heaping 1 ½ Tbsp scoops onto prepared cookie sheets. Bake on 350F (177C) for 11-13 minutes (cookies will appear slightly underbaked still -- this is fine and they'll finish baking on the cookie sheet). Allow cookies to cool completely on cookie sheet before removing.