Thaw peaches, if frozen (do not drain). Preheat the oven to 350 degree F. In a 2-quart square baking dish, arrange peach slices. Sprinkle peaches with 1/2 cup sugar; set aside.
In a small bowl, stir together the self-rising flour and 1/2 cup sugar. Using a pastry blender, cut in butter until crumbly. Sprinkle mixture evenly over the peaches. Bake, uncovered, in the preheated oven about 45 minutes or until topping is golden brown and filling is bubbly around the edges. Let cool slightly before serving. Makes 6 to 8 servings.