Bring a large pot of lightly salted water to a boil. Cook spaghetti in the boiling water, stirring occasionally until "al dente" (cooked through but firm to the bite), about 12 minutes. Drain.
Heat a large skillet over medium-high heat. Cook and stir beef in the hot skillet until browned and crumbly, 5 to 7 minutes, drain and discard grease.
Place beef in a bowl and mix with spaghetti sauce.
Combine the cream cheese, Smith's sour cream and Smith's cottage cheese until well blended.
Place half the slices of butter into the bottom of a 9" x 13" casserole dish. Spread half the spaghetti into the dish. Top spaghetti with creamy mixture. Layer remaining spaghetti over creamy mixture. Top with remaining pats of butter. Pour ground beef mixture over spaghetti and spread to cover casserole.
Bake in the preheated oven for 30 minutes.
Spread Cheddar cheese over pasta and continue baking until cheese has melted and is lightly browned, about 15 more minutes.