Prep: 45 minutes Bake 20 minutes Oven 400 degrees
For topping, in a medium bowl stir together flour, sugar, baking powder and cinnamon. Cut in butter or margarine till mixture resembles coarse crumbs. Set aside.
For filling in a sauce pan combine rhubarb, sugar, cornstarch and water. Cook and stir until thickened and bubbly. Keep filling hot.
In a small bowl stir together the egg and milk. Add to flour mixture, stirring just to moisten. Transfer filling to a 2 quart square baking dish. Using a spoon, immediately drop topping into small mounds atop filling.
Bake cobbler in a 400 degree oven for 20 minutes or till a wooden toothpick inserted into topping comes out clean. If desired serve warm with ice cream.