Preheat oven to 400 degrees.
(1) Melt 1/2 stick butter in 13x9 metal baking pan.
(2) In heavy saucepan, combine 1-28 oz can peaches (undrained), 1 cup sugar, 1/2 cup water. Bring to a boil.
(3) in small bowl, combine 3/4 cup water & 1 heaping tablespoon cornstarch and add to peach mixture. Return to boil.
(4) In mixing bowl, combine 1-1/2 cups sugar, 1-1/2 cups self-rising flour, 2 teaspoons vanilla and enough milk to make a thin batter. (a little thinner than a pancake batter).
(5) Pour hot peaches into pan with melted butter, and pour batter all over peach mixture. Top with cinnamon/sugar mixture, (1/2 cup sugar, 1/2 tsp cinnamon) and bake for 30 minutes or until golden brown.