Preheat the oven to 350˚F.
Cook the spaghetti in boiling water until al dente. Drain and set aside.
In a large skillet, cook the ground beef over medium high heat until no longer pink, around 5-7 minutes. Drain and discard the grease. Mix in the tomato sauce.
Evenly arrange the slices of butter at the bottom of a 9x13 inch casserole dish. Set aside.
In a medium bowl, mix together the cottage cheese, cream cheese and sour cream.
Spread half of the spaghetti in casserole dish on top of the butter. Spread half of the cottage cheese mixture on top, then half of the ground beef mixture. Repeat with the remaining spaghetti, cottage cheese mixture and ground beef mixture.
Bake in the preheated oven for 30 minutes. Remove from the oven and spread the shredded cheese on top. Return to the oven and bake for an additional 15 minutes.