In a large bowl, mix the cake mix, pudding mix, oil, eggs and vanilla until completely combined and dough forms.
Stir in the 1/2 cup sprinkles and 3/4 cup chocolate chips.
With a cookie scoop or just a spoon, scoop cookie dough balls onto baking sheets. I used an additional 1/4 cup Halloween chocolate chips to press into the tops of each cookie to make them very festive.
Bake for 8-10 minutes, or until slightly golden brown. The centers will still be very soft. Cool for at least 10 minutes before serving.