In a large pan, brown the ground beef over medium-high heat. Drain the meat, then return it to the pan. Add the spaghetti sauce, tomatoes, and butter, then bring to a simmer.
Once the sauce is simmering, reduce the heat to low. Then, preheat the oven to 375℉.
Bring a large pot of well salted water to a boil. Then, cook the spaghetti for 6 minutes. It should still be al dente, with a bit of crunch when you drain it. It will finish cooking in the oven.
Add the spaghetti to the sauce, then stir well to thoroughly coat the noodles. Spread about half of the spaghetti across the bottom of a 9x13 oven safe baking dish. Then, add a layer of ricotta, using about half the cheese.
Repeat these layers once more. Then, top with plenty of shredded mozzarella cheese. Bake for 30 minutes. Then, finish under the broiler for a few minutes. Watch closely, and remove immediately once it has the desired golden brown crust.
