Cook the pasta according to package instructions until al dente. Reserve about 1/2 cup of the pasta water before draining.
Heat olive oil in a large skillet over medium heat. Add minced garlic and sauté for about 1-2 minutes until fragrant.
Add crumbled feta cheese, heavy cream (or milk), fresh lemon juice, and lemon zest into the skillet. Stir until the feta begins to melt and form a smooth sauce.
If the sauce is too thick, gradually add reserved pasta water until desired consistency is reached.
Stir in red pepper flakes, salt, and pepper to taste.
Toss the cooked pasta into the skillet with the creamy sauce and stir until well-coated.
Garnish with freshly chopped basil or parsley and sprinkle with grated Parmesan cheese if desired.