Streusel Topping 1/3 cup  all-purpose flour 1/4 cup granulated sugar 1/4 cup brown sugar 1/2 teasp cinnamon 3    tablesp cold unsalted butter Batter 3 cups thinly sliced fresh or frozen rhubarb 2 cups all-purpose flour 2 to 3 large oranges 1/4 cup of butter, melted 1 egg 1 teasp vanilla 1/2 cup granulated... more