Ingredients
FILLING:3 cups sliced fresh or frozen rhubarb (1-inch pieces)1 quart fresh strawberries, mashed2 tablespoons lemon juice1 cup sugar1/3 cup cornstarchCAKE:3 cups all-purpose flour1 cup sugar1 teaspoon baking powder1 teaspoon baking soda1/2 teaspoon salt1 cup butter, cut into pieces1-1/2 cups buttermilk2 large eggs, room temperature1 teaspoon vanilla extractTOPPING:1/4 cup butter3/4 cup all-purpose flour3/4 cup sugar
Preparation
In a large saucepan, combine rhubarb, strawberries and lemon juice. Cover and cook over medium heat about 5 minutes. Combine sugar and cornstarch; stir into saucepan. Bring to a boil; cook and stir 2 minutes or until thickened. Remove from heat and set aside.
Preheat oven to 350°. In a large bowl, combine flour, sugar, baking powder, baking soda and salt. Cut in butter until mixture resembles coarse crumbs. Beat buttermilk, eggs and vanilla; stir into crumb mixture.
Spread half of the batter evenly into a greased 13x9-in. baking dish. Carefully spread filling on top. Drop remaining batter by tablespoonfuls over filling.
For topping, melt butter in a saucepan over low heat. Remove from heat; stir in flour and sugar until mixture resembles coarse crumbs. Sprinkle over batter. Lay foil on lower oven rack to catch any juice spillovers.
Place coffee cake on middle rack; bake 40-45 minutes. Cool on a wire rack.
