Preheat your oven to 350 degrees, and grease a 9"x13" baking dish.
Cook spaghetti noodles according to package directions. Drain the noodles then add one (24 ounce) can of the spaghetti sauce.
In a large skillet, cook the ground beef, drain and set it aside in a different container.
Next add the olive oil to the empty skillet and place the onions and garlic in skillet and sauté for 3-4 minutes.
Add the meat back in the skillet and add the other jar of spaghetti sauce.
In a medium bowl add the cottage cheese, cream cheese, sour cream, and 1 cup of the mozzarella. Next add parsley, garlic powder, and pepper.
Place 1/2 of the sliced butter into the bottom of the baking dish. Next place 1/2 the spaghetti noodles mixture in the dish, then 1/2 the cheese mixture evenly over the spaghetti noodles mixture.
Add the remaining spaghetti noodles mixture over cheese mixture and top with remaining butter slices.
Pour the meat sauce mixture evenly over the top layer of the spaghetti noodles mixture.Then add the other 1/2 of the cheese mixture evenly over the meat sauce mixture.
Top with the last 2 cups mozzarella.
Bake uncovered for 30-40 minutes, or until the casserole is heated through to the center.