Preheat your oven to 375°F (190°C). Cook 1 lb of cavatappi pasta according to package directions until al dente.
Make the creamy cheese sauce: In a large oven-safe skillet, melt 6 tablespoons of butter over medium heat. Whisk in ½ cup of flour. Next, slowly whisk in 4 cups of half-and-half until the sauce is smooth. Let it simmer for 3–5 minutes to thicken. After, reduce the heat to low, stir in 2 cups Gruyere, 1 cup white cheddar, ½ cup Parmesan, and ½ cup fontina until smooth.
Combine everything: Stir the cooked pasta into the cheese sauce. Season with salt and pepper.
Make the topping: In a small bowl, melt the remaining 2 tablespoons of butter. Mix with 1 cup of panko and ½ teaspoon of paprika.
Bake and serve: Sprinkle the panko mixture and ½ cup cooked bacon over the mac and cheese. Bake for 15-20 minutes until bubbly and golden. Sprinkle chopped fresh parsley before serving, if you like.