Butter for greasing the pan
For the shrimp
1 tablespoon unsalted butter
1 pound shrimp, peeled, deveined and chopped into 1/2-inch pieces
1/2 teaspoon Creole seasoning
For the pasta
1 pound cavatappi pasta, cooked al dente according to package directions
1/4 cup unsalted butter
1/4 cup all-purpose flour
3 cups whole milk
1/2 cup shredded sharp cheddar cheese
1/2 cup shredded Gruyere cheese
1/2 cup shredded Gouda cheese
1/2 cup shredded Parmesan cheese
1 teaspoon Creole seasoning, divided
Salt
Freshly ground black pepper, to taste
For the topping
1/4 cup unsalted butter, melted
1 cup Panko breadcrumbs
2 tablespoons minced parsley
Preheat the oven to 400 degrees F. Butter a 9-by-13-inch baking dish.
To prepare the shrimp, melt the butter in a large skillet set over medium heat.
Add the shrimp and seasoning and cook, stirring occasionally, for about 4 minutes, until the shrimp is cooked through. Remove the pan from the heat.
To prepare the pasta, melt the butter in a large saucepan set over medium heat. Whisk in the flour and cook, whisking constantly, until the flour starts to brown, about 5 minutes.
While continuing to whisk, add the milk in a slow, steady stream and bring to a simmer.
Stir in the cheeses, one type at a time, stirring after each addition until it is melted and incorporated before adding the next.
Stir in the seasoning and add salt and pepper to taste. Remove the pot from the heat and then stir in the cooked pasta until well coated.
Transfer the pasta and sauce to the prepared baking dish.
Make the topping by tossing the melted butter with the bread crumbs and parsley until well-combined. Sprinkle the mixture evenly over the pasta in the baking dish.
Bake in the preheated oven for 15 to 20 minutes, until the top is lightly browned and the sauce is bubbling. Remove from the oven and let sit for about 10 minutes before serving.