Preheat oven to 350.

Line a 9x9” pan with foil and spray with non-stick spray.

Stir cake mix, butter, and egg until a thick dough forms.

Add 1/3 cup sprinkles and stir until well distributed.

Press 1/2 of this mixture into the bottom of the pan.

Top with white chocolate chips and the other 1/3 cup sprinkles.

Pour condensed milk over the top.

Break remaining dough into small pieces and place evenly over the top of the bars. Press and flatten to form a complete layer.

Bake 30 minutes or until top begins to brown.

Cool completely before slicing.