"A riff on the classic gooey butter cake, these custardy dessert bars (made easy with Betty Crocker™ yellow cake mix!) are filled with chopped rhubarb. If you only have fresh rhubarb on hand, or it’s not in season and frozen is available, this recipe can work equally well with whichever you have on hand. Serve with a scoop of vanilla ice cream, or top with a from-scratch sweetened whipped cream for an added level of deliciousness! It’s a great potluck treat and travels well...."