1 yellow cake mix
1 stick (1/2 cup) butter, softened
2/3 cup sprinkles, divided
1/2 cup (from a 14 ounce can) sweetened condensed milk
1 cup white chocolate chips
Preheat oven to 350 degrees. Line a 9x9" pan with foil and spray liberally with cooking spray.
Add cake mix, butter, and egg to the bowl of an electric mixer fitted with a paddle attachment.
Mix until a thick dough forms.
Add 1/3 cup sprinkles and stir until incorporated.
Press about 2/3 of the dough into the bottom of the prepared pan.
Sprinkle with white chocolate chips and remaining 1/3 cup sprinkles.
Pour sweetened condensed milk over the top. Separate remaining dough into small balls and evenly space over the top of the bars.
Press down to flatten.
Bake bars for about 30 minutes, or until they just begin to brown.
Cool completely before slicing, otherwise the mixture will be too gooey to cut.
Optional: eat straight from pan with a fork.