1. Preheat your oven to 350°F (175°C).
2. Cook the macaroni according to the package instructions until al dente. Drain and set aside.
3. In a large saucepan, melt the butter over medium heat. Stir in the flour and cook for about 1 minute, until golden and bubbly.
4. Slowly whisk in the milk and heavy cream, continuing to whisk until the mixture is smooth and begins to thicken, about 3-5 minutes.
5. Reduce the heat to low and add the cheddar, Gruyere, and Parmesan cheeses, stirring until completely melted and the sauce is smooth.
6. Stir in the Dijon mustard, garlic powder, smoked paprika, and season with salt and pepper to taste.
7. Add the cooked macaroni to the cheese sauce, stirring until the pasta is well coated.
8. Transfer the mixture to a greased baking dish.
9. In a small bowl, combine the panko breadcrumbs with olive oil, mixing until the breadcrumbs are evenly coated. Sprinkle over the macaroni and cheese.
10. Bake in the preheated oven for 20-25 minutes, or until the top is golden brown and crispy.
11. Garnish with fresh parsley before serving, if desired.

As you follow these steps, remember that cooking is an expression of love, a lesson Nonna Rosa instilled in me. Don’t be afraid to taste and adjust the flavors as you go!