Bring a large pot of salted water to boil and cook penne pasta according to package directions until al dente. Reserve 1 cup of pasta cooking water before draining.

While pasta cooks, heat a large skillet over medium heat and cook chopped bacon until crispy, about 6-8 minutes. Remove bacon with slotted spoon and set aside, leaving 2 tablespoons of fat in pan.

Add minced garlic to the bacon fat and sauté for 30 seconds until fragrant, being careful not to burn.

Pour in heavy cream and bring to a gentle simmer. Let cook for 2-3 minutes to slightly reduce and thicken.

Add the cooked peas to the cream sauce and cook for 1-2 minutes until heated through.

Add the drained pasta to the skillet with the cream sauce and toss to combine. If sauce seems too thick, add reserved pasta water gradually until desired consistency is reached.

Remove from heat and stir in grated Parmesan cheese until melted and smooth.

Add the crispy bacon back to the pasta and toss gently to distribute evenly.

Season with salt, black pepper, and red pepper flakes if using. Taste and adjust seasoning as needed.

Garnish with fresh chopped parsley and serve immediately with additional Parmesan cheese on the side.