Boil the spaghetti in a large pot of well salted water for 1 minute less than the package time, until firm to the bite. Drain, toss with 1 tablespoon of olive oil, and set aside.

Heat 1 tablespoon of oil in a deep skillet over medium heat, cook the onion for 4 minutes, then add the garlic for 30 seconds. Crumble in the beef and cook 7 to 8 minutes, until no pink remains and the pieces look browned.

Drain any extra fat, then stir in the crushed tomatoes, tomato sauce, tomato paste, broth, Italian seasoning, salt, pepper, sugar, and pepper flakes. Simmer for 15 to 20 minutes, until the sauce is thick enough to mound on a spoon.

Beat the cream cheese for 1 minute until smooth, then beat in the cottage cheese, egg, garlic powder, salt, and parsley. The mixture should look creamy and slightly textured, with no lumps of cream cheese.

Split the pasta in half, then toss each half with 1 1/2 cups of the sauce, until every strand looks coated.

Spread half of the sauced pasta in the dish, then spoon the cheese layer on top and spread it to the edges. Add the remaining pasta, spread the leftover sauce over the top, and cover with the mozzarella and provolone.

Cover the dish with foil, set it on the baking sheet, and bake at 350°F for 25 minutes. Remove the foil and bake 15 to 20 minutes more, until the cheese is melted and golden and the center reaches 165°F.

Let the casserole rest for 10 minutes, so the cheese layer sets and the squares cut clean. Garnish with parsley and serve hot.