- In a large bowl, combine rhubarb, blueberries, honey, sugar, orange juice and cornstarch. Place into a lightly greased 8x8-inch baking pan. In a small bowl, combine oats, flour, brown sugar and pecans. Sprinkle oat mixture evenly over rhubarb mixture. Dot the top with butter. Bake in a preheated 350 F oven for 60 minutes. Remove from oven and serve warm with ice cream.