In a large bowl, mix the entire box of cake mix with ½ cup of sprinkles.
Mix in oil, egg, and heavy cream until well combined.
Add in white chocolate chips.
Scoop batter inside a greased 9x12 or 8x8 pan and flatten. Batter should be thick.
Top with remaining sprinkles.
Bake for 20-30 minutes until the edges are brown and a toothpick comes out clean when inserted into the middle. The center may be gooey.
Cool the bars completely for about 45-60 minutes before cutting them.
Notes
This Recipe Can be Doubled: This is an amazing recipe for events and bake sales, and will be one of everyone's favorite desserts. Simply increase the ingredients proportionately and split into multiple pans before baking. Cut into squares once cooled for an easy snack.
Don't Overbake: If the center is gooey after the baking time, take them out. After 30 minutes of cooling these white chocolate blondies will be chewy and easy to cut.
Cloudy Batter: Some sprinkles, such as black or other colors, bleed if they are left in the batter too long before baking. Look for confectioners glaze in the ingredients list when purchasing sprinkles. This prevents the dyes from bleeding into the batter.