Preheat oven to 350°. Line a cookie sheet with parchment paper and set aside.
Add the cake mix, eggs, oil and vanilla into a mixing bowl. Mix well to combine all ingredients.
The dough will be a bit sticky so chill for 30 minutes for easier handling.
Roll the chilled dough into 1 inch balls and dip into the purple sugar crystals. Place on the cookie sheet, 2 inches apart. Flatten each ball slightly with the back of a fork.
Bake for 8-10 minutes.
Remove from oven and cool on cookie sheet for 5 minutes before transferring to a wire rack to completely cool.