Preheat oven to 350 degrees F.

Line three cookie baking sheets with parchment paper or silicone baking mat. Set aside.

In a large bowl, beat together white cake mix (just the dry mix), eggs, vegetable oil, all-purpose flour and vanilla extract until smooth (about two minutes with electric hand mixer).

Separate cookie batter equally into 6 small bowls. Color one bowl red, one orange, one yellow, one green, one blue and one purple.

To fully combine the colors into each cookie batter bowl, spray your hands very lightly with non-stick cooking spray then carefully squish and knead each bowl of dough to completely combine color into dough. Wash hands between each bowl so you don’t mix colors.

Scoop cookies onto baking sheets (place cookies at least two inches apart). Cookies should be 2-tablespoons in size (30 grams each). Roll each cookie into a ball shape before baking.

Bake each cookie sheet separately. Each cookie tray will need to bake for 12-13 minutes. Cookies should rise and the tops will look set. Let cookies cool completely on the baking sheet before removing.

Store covered in a food storage container at room temperature for up to 4 days.