Rhubarb Elderberry Crisp Recipe

In a large bowl, combine the flour, oats, 1/2 cup sugar and cinnamon; cut in butter until mixture resembles coarse crumbs. Set aside half for topping. Press remaining crumb mixture into an ungreased 11-in. x 7-in. baking dish. Top with rhubarb and berries. In a small saucepan, combine cornstarch and remaining sugar. Gradually stir in water; bring to a boil. Reduce heat; cook and stir for 1-2 minutes or until thickened. Remove from the heat; stir in vanilla. Pour over the fruit. Sprinkle with the reserved crumb mixture. Bake at 350 ° for 50-55 minutes or until golden brown. Serve warm or cold.