Preheat your oven to 350°F (175°C) for even baking.

In a large pot, bring salted water to a boil. Add spaghetti and cook until al dente, about 12 minutes. Drain and set aside.

In a skillet over medium-high heat, cook ground beef until browned and crumbly, about 5–7 minutes. Drain excess grease, then mix the beef with the spaghetti sauce and set aside.

Place half of the butter slices in the bottom of a 9x13-inch casserole dish. Spread half of the cooked spaghetti over the butter.

In a bowl, mix together cottage cheese, cream cheese, and sour cream until smooth and blended. Spread this cheese mixture over the spaghetti layer in the casserole dish.

Add the remaining spaghetti over the cheese layer. Top with the remaining butter slices. Pour the ground beef and sauce mixture over this layer, spreading it out evenly.

Place the casserole dish in the oven and bake for 30 minutes. Remove from the oven, sprinkle the top with shredded Cheddar cheese, and return to bake for an additional 15 minutes, until cheese is melted and lightly browned.

Once done, remove from the oven and let the casserole cool for a few minutes. Scoop and serve while hot!