1/2 c. (1 stick) butter, melted
1 c. self-rising flour
1 3/4 c. sugar
1 c. milk
1 can blueberry pie filling

Pour butter in a 9-inch baking pan. Mix flour and sugar in a bowl. Slowly add milk and stir. Pour over melted butter, but do not stir. Spoon pie filling over batter and bake at 300°F for 1 hour. To serve, top with whipped topping.