Cook the pasta according to package instructions in a large pot of salted boiling water until al dente. Reserve 1/2 cup of pasta water, then drain the pasta and set aside.
In a large skillet over medium heat, cook the chopped bacon until crispy, about 5 minutes. Remove the bacon with a slotted spoon and drain on paper towels, leaving the bacon fat in the skillet.
Add the minced garlic to the skillet and sauté for about 30 seconds until fragrant.
Pour in the heavy cream and bring to a simmer. Stir in the Parmesan cheese, salt, black pepper, and red pepper flakes (if using). Cook for 2-3 minutes until the sauce thickens slightly.
Add the cooked pasta to the skillet, tossing to coat in the creamy sauce. If the sauce is too thick, add reserved pasta water a little at a time until desired consistency is reached.
Stir in the crispy bacon and mix well.
Serve immediately, garnished with chopped parsley.