Bring a large pot of salted water to a boil. Cook the past according to package directions until al dente. Drain, reserving ½ to 1 cup of starchy pasta water for the sauce.
While the pasta is cooking, place a 12-inch cast-iron skillet over medium heat. Add the bacon and cook, flipping at least once, until crisp and browned.
Remove the bacon to a paper-towel lined plate. Carefully pour off the excess grease, leaving about 1 to 2 tablespoons in the skillet. Keep those flavorful browned bits in the pan - that's where the flavor lives!
Add the minced garlic to the skillet and sauté until fragrant, about 30 seconds. Do not let it brown or it will become bitter.
Pour in the half-and-half. Use a wooden spoon to gently scrape the bottom of the pan to release the browned bits from the bacon.
Stir the broccoli florets into the sauce and simmer for 2 to 3 minutes until the broccoli is bright green and starting to get tender. Do not overcook or the broccoli will get mushy.
While broccoli is simmering, chop the cooled bacon into ½ pieces.
Stir in the black pepper and red pepper flakes. Let the sauce simmer uncovered for another 2 to 3 minutes until it begins to thicken.
Add the cooked pasta directly into the skillet. Sprinkle the grated Parmesan over the top and toss to coat.
Add a splash or two of the reserved pasta water until it reaches a silky consistency. You can add more, a tablespoon at a time, until the sauce reaches a consistency of your preference.
Gently fold in the crispy chopped bacon at the very end.
Serve immediately. Garnish with extra Parmesan and a final crack of fresh black pepper. If needed, add a pinch of salt to taste.