Cook the Pasta

1. Boil Water: In a large pot, bring salted water to a boil.
2. Add Pasta: Cook the elbow macaroni or cavatappi according to package instructions until al dente. Drain and set aside.

Prepare the Cheese Sauce

1. Melt Butter: In a large saucepan over medium heat, melt 4 tablespoons of unsalted butter.
2. Add Flour: Whisk in 1/4 cup of all-purpose flour, stirring constantly for about 2 minutes until golden and bubbly.
3. Add Milk: Gradually whisk in 3 cups of whole milk, ensuring there are no lumps.
4. Season Sauce: Stir in garlic powder, onion powder, Dijon mustard, cayenne pepper (if using), salt, and black pepper. Cook for about 5 minutes, until the sauce thickens.
5. Add Cheese: Reduce heat to low, then gradually stir in the shredded sharp cheddar and grated Parmesan until melted and smooth.

Combine Pasta and Seafood

1. Mix Pasta and Seafood: In a large mixing bowl, combine the cooked pasta, chopped lobster, lump crab meat, and cooked shrimp.
2. Add Cheese Sauce: Pour the cheese sauce over the pasta mixture, stirring gently to combine.

Bake the Dish

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Transfer to Baking Dish: Pour the mixture into a greased 3-quart baking dish.
3. Bake: Bake in the preheated oven for 25-30 minutes until bubbly and golden on top.

Serve

1. Cool Slightly: Remove from the oven and let cool for a few minutes.
2. Enjoy: Serve warm, garnished with fresh herbs if desired.