Prep. Preheat the oven to 350ºF. Line 2 baking sheets with parchment paper and set aside.
Combine the dry ingredients. In a large mixing bowl, whisk together the cake mix and baking powder; set aside.
Combine the wet ingredients. In a separate bowl, whisk together the eggs, oil, and vanilla until combined, and the mixture is pale yellow. Add the egg mixture to the cake-mix mixture; stir until thoroughly incorporated.
Transfer to the baking sheet. Drop 1-inch rounded balls of dough, two inches apart, onto the baking sheets. Add a few sprinkles on top of each dough ball and press lightly so they do not roll off. Do not flatten the cookie dough balls.
Bake. Bake the cookies for 9 minutes.
Remove and let cool. Remove the Funfetti cookies from the oven and let them stand for 2 minutes on the baking sheet. Then, transfer the cookies to a wire rack and cool completely before serving.
Notes
Room Temperature Ingredients: For more consistent results, use eggs that are at room temperature before mixing them in.
Don't Overbake: Monitor the baking closely. A 9-minute bake time will keep the cookies tender and soft.