Bring a large pot of salted water to a rolling boil. Add the elbow macaroni and cook for 8-10 minutes, or until al dente. Drain the pasta in a colander and set aside.

In a skillet over medium heat, warm the olive oil or butter. Add the shrimp and scallops, sautéing for 2-3 minutes until the shrimp turns pink and the scallops are opaque. Remove from heat, fold in lump crab meat, and season lightly with salt and pepper.

In a saucepan, melt the unsalted butter over medium heat. Whisk in the flour to form a roux, cooking for 1-2 minutes until golden. Gradually add the warmed milk and heavy cream, stirring until the sauce thickens slightly, about 5 minutes. Mix in the Dijon mustard, Old Bay seasoning, garlic powder, salt, and black pepper off the heat.

Return the saucepan to heat if necessary, and stir in the sharp cheddar, Gruyère, and Parmesan cheese into the sauce until melted and smooth.

Carefully add the cooked pasta and the sautéed seafood mixture to the cheese sauce. Stir gently until everything is evenly coated.

Preheat your oven to 375°F (190°C). Transfer the mixture into a buttered baking dish. Mix panko breadcrumbs with melted butter and grated Parmesan, then sprinkle over the top. Bake for 20-25 minutes until golden and crispy.

Let the Seafood Mac and Cheese rest for 5 minutes after baking. Serve warm and enjoy!