In a large skillet over medium heat, add 2 tablespoons of olive oil. Toss in 1 pound of peeled and deveined shrimp seasoned with 1 tablespoon of Cajun seasoning. Sauté for about 4-6 minutes, or until the shrimp turn pink and opaque. Once cooked, remove from heat and set aside to let them cool while you prepare the pasta.

Bring a large pot of salted water to a boil. Add 8 ounces of elbow macaroni and cook until al dente, typically 6-8 minutes. Once cooked, drain the pasta and return it to the pot. Mix in the sautéed shrimp, 8 ounces of crab, and a handful of fresh basil, gently folding the ingredients together until well combined.

In a medium bowl, whisk together 2 cups of whole milk, 1 cup of evaporated milk, and 2 beaten eggs until smooth. Stir in 1 teaspoon of paprika, 1/2 teaspoon of cayenne pepper, and a pinch of salt and black pepper. This creamy mixture will bind the Cajun Shrimp and Crab Mac and Cheese, adding rich texture and flavor to your dish.

Add 3 cups of mixed cheeses to the milk mixture, stirring until the cheese is fully melted and incorporated. Pour this cheesy milk blend over the pasta and seafood mixture, ensuring everything is evenly coated. Stir gently for a cohesive mix packed with Cajun flavors.

Preheat your oven to 350°F (177°C). Grease a 9x13-inch baking dish with cooking spray or butter. Pour the creamy pasta mixture into the prepared dish, spreading it out evenly. Sprinkle reserved cheese on top and season with additional Cajun spices if desired. This will create a golden crust when baked.

Cover the dish with aluminum foil and place it in the preheated oven. Bake for 45-55 minutes, or until the top is golden brown and bubbly. Remove from the oven and let the Cajun Shrimp and Crab Mac and Cheese rest for 20-30 minutes before serving; this resting time allows the flavors to meld perfectly and the dish to set up beautifully.