Preheat your oven to 350°F (175°C).

Cook the spaghetti or linguine in salted boiling water until al dente. Drain and set aside.

In a large skillet, melt the butter over medium heat. Add garlic and red pepper flakes, sauté until fragrant.

Add the shrimp to the skillet and cook until they turn pink, about 2-3 minutes.

Pour in the heavy cream and bring to a gentle simmer. Stir in Parmesan cheese until melted and creamy.

Combine the cooked pasta, shrimp, and sauce in a large mixing bowl. Season with salt and pepper, then mix in parsley.

Transfer the mixture to a greased baking dish. Top with additional Parmesan and breadcrumbs if desired.

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

Remove from the oven and let it cool for a few minutes before serving. Garnish with more parsley.