Preheat oven to 425 degrees F. In an extra-large skillet, cook ground beef over medium heat until brown; drain off fat. Stir the 1/4 cup flour and the dry onion soup mix into meat. Stir in soup, sour cream, the 3/4 cup water, and the ketchup. Cook until heated through, stirring occasionally.
Meanwhile, in a medium saucepan, combine the 1-1/2 cups water, the butter, and salt. Bring to boiling; remove from heat. Add dry potato flakes and milk, stirring until combined. Stir in eggs, the 1 cup flour, and the baking powder.
Spoon meat mixture into an ungreased 3-quart rectangular baking dish; spoon potato mixture in mounds on top of meat mixture.
Bake, uncovered, about 25 minutes or until tops of potatoes are golden. Makes 8 servings.