Preheat the oven to 350°F and lightly spray a 12-cup muffin pan with cooking spray.
Cook the spaghetti according to package directions until al dente, drain, and transfer to a large bowl.
Toss the hot spaghetti with the melted butter, then stir in the whisked eggs and 1/2 cup grated Parmesan until the pasta is evenly coated.
Press portions of the spaghetti into the prepared muffin cups, dividing the pasta evenly among the 12 cups and compacting to form cups.
While the pasta cooks, brown the Italian sausage in a skillet over medium heat, breaking it up; drain excess fat then stir in the 2 cups of spaghetti sauce and remove from heat.
In a small bowl, combine the cottage cheese, 1/4 cup Parmesan, and dried parsley.
Divide the cottage cheese mixture evenly among the spaghetti cups.
Spoon the sausage and sauce mixture over each cup (you may have a little sauce left) and top each with shredded mozzarella.
Bake for 30 minutes, or until the cheese is lightly browned and the pies are heated through; let cool a few minutes before removing from the pan.