In a large bowl, mix together 1 box Funfetti cake mix, 2 eggs, and 1/3 cup oil until fully combined. The batter will be thick. If using sprinkles, fold in 2–3 tablespoons sprinkles or reserve them for topping after baking.
Drop spoonfuls of dough onto cookie sheets, leaving about 2 inches between each cookie.
Bake for 8 to 10 minutes, until the cookies are slightly browned on the edges.
Remove from the oven and immediately top with additional sprinkles if desired. Allow cookies to cool completely before serving.
Notes
You can roll your cookies in sprinkles before baking or add sprinkles fresh out of the oven.