Preheat the oven to 350 degrees.
Prep the baking dish with nonstick spray.
Add the 2 boxes of cake mix, canola oil, eggs.
Stir to mix well.
Slowly stir in the milk.
(The batter will be thick.)
Slowly stir in half of the sprinkles and white chocolate chips.
Scoop the batter into the baking dish.
Add more sprinkles and white chocolate chips to the top of the batter.
Bake at 350 degrees for 30-35 minutes. (or until the edges begin to turn brown)
Remove from the oven.
Set aside for at least 30 minutes. (This will allow for the center to set.)
Cut into bars and enjoy!