Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish or similar-sized casserole dish and set aside.

Cook the pasta according to package instructions, rinse in cold water, drain and set aside.

In a large saucepan, melt the butter over medium heat. Once melted, whisk in the flour and cook for 1-2 minutes, stirring constantly, until the mixture is golden and smooth.

Gradually whisk in the evaporated milk and half & half, ensuring there are no lumps. Cook, stirring frequently, until the mixture thickens, about 3-4 minutes.

Stir in the onion powder, garlic powder, Old Bay seasoning, salt, and black pepper. Mix well to combine.

Reduce the heat to low and add 1/2 cup each of the mozzarella, sharp white cheddar, and Gouda cheeses. Stir until the cheeses are fully melted and the sauce is smooth.

Add the cooked cavatappi pasta to the cheese sauce and stir until the pasta is evenly coated. Gently fold in the shrimp and imitation crab meat, being careful not to break up the seafood too much.

Transfer the mac and cheese mixture to the prepared baking dish, spreading it out evenly. Sprinkle the remaining 1/4 cup each of mozzarella, sharp white cheddar, and Gouda cheeses evenly over the top.

Bake in the preheated oven for 15-20 minutes, or until the top is bubbly and slightly golden. Remove from the oven and let it rest for 5 minutes before serving. Enjoy!