Preheat the oven to 350°F (175°C) and coat a baking sheet with cooking spray.

In a large mixing bowl, combine white cake mix, vanilla pudding mix, eggs, softened butter, and milk. Mix until well incorporated.

In a small bowl, mix red and green decorating sugars.

Scoop out portions of dough, roll into balls, and coat in decorating sugars.

Arrange the dough balls on the baking sheet, spaced 2 inches apart.

Bake for 8-10 minutes until set at the edges but soft in the center.

Let cookies cool on the baking sheet for about a minute, then transfer to a wire rack to cool completely.