This is my most favorite Italian recipe. I don't remember where I got this recipe from, but I love to make this when company comes over. Serve with a salad and some warm garlic bread. It's the next best thing to being in heaven!
Bring a lg. pot of lightly salted water to a boil. Cook pasta in boiling water for 8 to 10 min., or until al dente; drain.
Meanwhile, heat olive oil in lg. heavy skillet over med. heat. Cook onion in oil until tender. Stir in rosemary and garlic. Transfer to a small bowl. Place ground beef and sausage in the skillet. Cook over med. high heat until evenly brown. Stir in the onion mixture and the spaghetti sauce. Season with salt. Reduce heat to low, and simmer for 10 min. Preheat oven to 350 degrees. Grease a 9x13 in. baking dish. In the prepared dish, layer 1/2 the cooked pasta, provolone cheese, sour cream, cottage cheese, and a little less than 1/2 of the meat mixture. Then layer the rest of the pasta, mozzarella cheese, remaining meat mixture, and Parmesan cheese. Bake in preheated oven for 20-30 minutes, or until heated through and cheeses are melted.