Bring a large pot of well-salted water to a boil. Cook 1 pound of elbow macaroni, cavatappi, or shells until 1–2 minutes shy of al dente. Drain and set aside.

Preheat your oven to 375°F and butter a 9×13-inch baking dish.

Warm 4 cups whole milk and 1 cup heavy cream in a saucepan or microwave until warm but not boiling.

Melt 6 tablespoons butter in a large pot over medium heat.

Whisk in 6 tablespoons all-purpose flour and cook for 2 minutes, stirring constantly, until it smells slightly nutty but has not browned.

Slowly whisk in the warm milk and cream until smooth.

Cook the sauce for 5–7 minutes, whisking frequently, until it thickens enough to coat the back of a spoon.

Stir in 1 teaspoon Dijon mustard, ½ teaspoon garlic powder, ½ teaspoon onion powder, 1 teaspoon kosher salt, and ½ teaspoon black pepper.

Remove the pot from the heat.

Gradually stir in 12 ounces shredded sharp cheddar, 8 ounces shredded Gruyère, and 4 ounces shredded Monterey Jack, stirring until completely smooth and creamy.

Add the cooked pasta and stir until every piece is coated in the cheese sauce.

Transfer the mac and cheese to the prepared baking dish.

In a small bowl, combine 1 cup panko breadcrumbs, 2 tablespoons melted butter, and ½ cup grated Parmesan cheese.

Sprinkle the breadcrumb mixture evenly over the mac and cheese.

Bake for 20–25 minutes, until bubbly around the edges and golden brown on top.

Let the mac and cheese rest for 10 minutes before serving.