In a skillet over medium heat, cook 4 slices of house smoked bacon until crisp. Transfer to paper towels to drain; reserve 1 tablespoon of the rendered fat for flavoring the roux.

Cook pasta

Bring a large pot of salted water to a boil. Add 2 cups elbow macaroni and cook until al dente, about 6-8 minutes. Drain and set aside.

Make the roux

In a medium saucepan, melt 2 tablespoons butter over medium heat. Whisk in 2 tablespoons flour and cook 1-2 minutes until lightly nutty. Slowly whisk in 2 cups milk and 0.5 cup heavy cream until smooth.

Finish the cheese sauce

Remove the milk mixture from heat and whisk in 2 cups shredded cheddar and 0.5 cup Parmigiano-Reggiano until fully melted. Season with 0.5 teaspoon salt and 0.25 teaspoon pepper; adjust to taste.

Combine pasta and sauce

Fold the drained macaroni into the cheese sauce until evenly coated. Stir in half of the crisp bacon bits.

Optional topping prep

If using breadcrumbs, toss 0.5 cup panko with 1 teaspoon olive oil and a pinch of salt. Set aside.

Bake or finish

If baking, transfer the mac and cheese to a baking dish. Top with the remaining bacon, breadcrumbs (if using), and a light drizzle of olive oil. Bake at 375°F (190°C) for 10-15 minutes, until bubbling and golden on top.

Garnish and serve

Sprinkle with chopped parsley (if using) and serve hot as a smoky, cheesy starter.