Preheat oven to 350 and grease a 9x13 baking pan with nonstick cooking spray. Set aside.

In a large bowl, combine cake mix, egg, milk and oil and mix well until a stiff dough forms.

Fold in white chocolate chips and 1 cup of m&m candies.

Fold in all but 1 tablespoon of jimmies.

Press dough into prepared pan and top with remaining m&m candies and jimmies.

Bake for 25-28 minutes or until brown and center is set.

Cool completely before cutting into 32 bars.