01 -
Line your 9-inch square pan with parchment paper. This makes it super easy to lift out later.
02 -
Dump your white chocolate chips, dry cake mix, and marshmallow fluff in a big bowl. Just leave them there for now.
03 -
Grab a pot and melt your butter, sugar, cream, and salt over medium heat. Keep stirring until it starts bubbling.
04 -
Once it's really bubbling, set your timer for 4 minutes. Keep stirring the whole time - no breaks!.
05 -
Pour the hot mixture over your bowl of chocolate and cake mix. Mix on low for a minute until the chocolate melts. Fold in most of your sprinkles.
06 -
Pour it in your pan and quickly sprinkle the rest of the rainbow sprinkles on top.
07 -
Now the hard part - leave it alone for 4 hours to set up properly.