Boil the Pasta: Cook the elbow macaroni in salted water according to package directions. Drain and set aside.
Make the Roux: In a medium saucepan, melt butter over medium heat. Stir in the flour and whisk constantly for about 2 minutes until golden.
Create the Sauce: Gradually add the milk and cream, whisking to eliminate lumps. Bring to a simmer, then reduce heat.
Add Flavor: Stir in the Dijon mustard, smoked paprika, garlic powder, salt, and pepper.
Melt the Cheese: Add cheddar, Monterey Jack, and mozzarella cheeses. Stir until melted and smooth.
Combine: Add the cooked pasta into the cheese sauce, stirring until evenly coated.
Prepare Topping: In a small bowl, mix the panko breadcrumbs with melted butter and Parmesan cheese.
Assemble and Bake: Transfer mac and cheese to a greased baking dish. Sprinkle the breadcrumb topping evenly over the pasta.
Bake: Cover with foil and bake at 350°F (175°C) for 20 minutes. Remove foil and bake for another 10-15 minutes until golden and bubbly.