Tart rhubarb and apples, sweetened and spiced and topped with oatmeal crunch, make an easy dessert.
Mix together flour, oats, brown sugar, spices, and melted butter. Press half of the mixture into the bottom of a 9-inch square baking pan. Arrange the rhubarb and apples evenly on top. Cook the white sugar, water, cornstarch, and vanilla until thick; pour over the rhubarb and apples. Sprinkle the remaining oatmeal mixture on top. Bake at 350 degrees F for 1 hour. Serve warm with ice cream or whipped cream.