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

2. Cook the elbow macaroni in salted boiling water until just al dente, then drain well.

3. Melt the butter in a large saucepan over medium heat.

4. Whisk in the flour and cook for 1 minute, stirring constantly.

5. Slowly whisk in the whole milk and heavy cream until smooth.

6. Cook the sauce for 3 to 5 minutes, whisking often, until slightly thickened.

7. Stir in Dijon mustard, garlic powder, onion powder, smoked paprika, salt, and black pepper.

8. Reduce the heat to low and add the shredded cheeses a handful at a time, stirring until melted.

9. Stir in the cream cheese until the sauce is smooth and creamy.

10. Fold the cooked macaroni into the cheese sauce until fully coated.

11. Transfer the mixture to the prepared baking dish.

12. Sprinkle breadcrumbs over the top if using, then add a little extra cheese if desired.

13. Bake for 20 to 25 minutes, until hot, bubbling, and lightly golden on top.

14. Let the mac and cheese rest for 5 minutes before serving, then garnish with fresh chives or parsley.