Preheat your oven to 350°F.

Cook the elbow macaroni according to package instructions until al dente, then drain and set aside.

In a large saucepan, melt the butter over medium heat.

Stir in the flour and cook for about 1 minute, whisking constantly until smooth.

Gradually add the milk, continuing to whisk until the mixture thickens, about 5-7 minutes.

Stir in the salt, black pepper, paprika, and cayenne pepper, if using.

Remove from heat and add the cheddar and mozzarella cheeses, stirring until melted and smooth.

In a large bowl, combine the cooked macaroni with the cheese sauce, mixing well to coat.

Transfer the mixture to a greased 9x13-inch baking dish.

Sprinkle the grated Parmesan cheese and breadcrumbs evenly over the top.

Bake in the preheated oven for 25-30 minutes, or until the top is golden brown and bubbly.

Let it cool for a few minutes before serving.