Rhubarb Crumble Bars Blueberry rhubarb crumble recipe, sugar can be adjusted to your preference.Crumb mixture ( press half onto pan, use the other half as topping) 3 cups all-purpose flour1 cup cold butter, cubed2/3 cup brown sugar1/4 cup cane sugar 1 teaspoon baking powder 1/4 teaspoon salt 1 beaten eggFilling:2 cups blueberries (any berry of your choice)3 cups slices rhubarb 1/2 cup to 3/4 cup cane sugar (rhubarb is tart)4 teaspoons cornstarch Bake in a preheated oven at 375 degrees Fahrenheit