Bring a large pot of lightly salted water to a boil. Cook the spaghetti until just al dente. Drain thoroughly and set aside.

Meanwhile, brown the ground beef in a large skillet over medium-high heat, breaking it into crumbles as it cooks. Drain off the excess grease.

Stir the spaghetti sauce into the cooked beef. Remove from the heat and set aside.

In a separate bowl, combine the cottage cheese, softened cream cheese, and sour cream. Stir until creamy and well blended.

Arrange half of the butter slices across the bottom of a 9×13-inch baking dish.

Spread half of the cooked spaghetti over the butter.

Spoon the cream cheese mixture over the pasta and gently spread it into an even layer.

Add the remaining spaghetti, followed by the rest of the butter slices.

Spread the beef and spaghetti sauce mixture evenly over the noodles.

Bake uncovered for 30 minutes.

Remove the casserole from the oven and sprinkle the shredded cheddar evenly over the top.

Return it to the oven and bake for another 15 minutes, or until the cheese is melted and the casserole is bubbling around the edges.

Allow the casserole to rest for 5 to 10 minutes before slicing and serving.