Preheat the oven to 350 F. Cook pasta according to package directions. Drain and place into a large bowl. Melt the butter in a large saucepan over medium heat. Cook garlic for a minute until it is fragrant.
Add in the flour, and cook for a minute to brown. Pour in the milk, 2 cups mozzarella cheese, grated parmesan cheese, salt, and pepper. Continue to cook over medium heat until the cheese has fully melted and the sauce has thickened.
Mix the sauce with the cooked pasta. Spread the pasta out into a greased baking dish. Top with mozzarella cheese. Bake for 20-25 minutes.