Cook spaghetti according to package directions; drain and place in bowl. Add the butter, eggs and Parmesan cheese; mix well.
Spread over the bottom and up the sides of a greased 10-in. deep-dish pie plate. Spoon cottage cheese into crust; set aside.
In a large skillet, cook the beef, onion and red pepper over medium heat until meat is no longer pink; drain.
Stir in the tomatoes, tomato paste, sugar, oregano and garlic salt. Spoon over cottage cheese. Bake, uncovered, at 350° for 20 minutes. Sprinkle with mozzarella cheese; bake for 5 minutes or until cheese is melted. Cut into wedges.