Cook the Linguine:
Bring a large pot of salted water to a boil. Add the linguine and cook according to the package directions until al dente (usually about 8-10 minutes). Drain the pasta, reserving about 1/2 cup of pasta cooking water.

Make the Garlic Butter Sauce:
While the pasta is cooking, melt the butter in a large skillet over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant and golden (be careful not to burn the garlic).

Add the Cream and Cheese:
Pour in the heavy cream and bring the mixture to a simmer. Reduce the heat and let it simmer for 2-3 minutes until slightly thickened.
Stir in the Parmesan and mozzarella cheeses until the sauce becomes smooth and creamy. Season with salt, pepper, and red pepper flakes (if using).

Combine Pasta and Sauce:
Add the drained linguine to the skillet, tossing to coat the pasta in the creamy garlic butter sauce. If the sauce is too thick, add a little reserved pasta cooking water to reach your desired consistency.

Garnish and Serve:
Once the pasta is fully coated, transfer to serving plates. Garnish with chopped fresh parsley and a sprinkle of freshly grated Parmesan cheese.

Enjoy:
Serve immediately and enjoy your creamy, cheesy garlic butter linguine!