Bring a large pot of salted water to a boil and add elbow macaroni. Cook until al dente, about 7-8 minutes. Drain and rinse with cool water.

In a medium saucepan, melt 4 tablespoons of unsalted butter over medium heat. Whisk in 4 tablespoons of all-purpose flour and cook for about 2 minutes.

Gradually add in 3 cups of whole milk, whisking continuously until the sauce thickens and is smooth, about 5-7 minutes.

Remove from heat and stir in 2 cups of shredded cheddar cheese and 1 cup of grated Parmesan cheese until melted.

Gently fold the cooked macaroni into the cheese sauce until fully coated.

Pour the pasta and cheese mixture into a greased casserole dish, spreading it evenly.

Cut ghost shapes from fresh mozzarella, then arrange on top of the casserole. Use sesame seeds or peppercorns for eyes.

Preheat your oven to 375°F (190°C) and bake for 20-25 minutes until bubbly and golden brown.

Let cool for a few minutes before serving. Spoon generous portions into bowls.