1. Preheat the oven to required temperature.
2. In a large bowl, add the butter, vanilla, egg and stir to mix.
3. Put the cake mix into this and stir well till it combines evenly.
4. To this add the sprinklers and mix.
5. Take a baking tray and spray the non-stick cooking oil.
6. Scoop some cookie mix and roll it in your palms and press gently to form patties.
7. Coat the cookies with the desired colour of sprinklers.
8. Bake it till the cookies are done.
9. Cool the cookies and transfer them onto a serving plate and enjoy.