Preheat your oven to 375°F (190°C) and generously grease a baking dish.

Boil a large pot of salted water and add the elbow macaroni. Cook until just al dente, about 7-8 minutes, then drain and set aside.

Melt the butter in a saucepan over medium heat. Whisk in the flour and stir constantly for 1–2 minutes to form a smooth roux.

Whisk in the milk and cream gradually. Cook and stir until the mixture is thickened and smooth, around 4-5 minutes.

Add the shredded cheddar and Gruyère cheeses to the mixture. Stir on low heat until fully melted and creamy, about 2-3 minutes.

Combine the cooked macaroni with the cheese sauce in a large bowl, stirring gently until every piece is evenly coated.

Pour this creamy mixture into the prepared baking dish, spreading it out evenly.

Mix the breadcrumbs with melted butter and the parmesan cheese in a small bowl. Sprinkle this topping over the pasta.

Bake for 20–25 minutes, or until the top is golden brown and bubbly.

Cool slightly before serving to allow the flavors to meld.