Cook pasta according to package directions, draining and reserving 1/4 cup pasta water.
While pasta is cooking, bring a medium pot of water to a boil and add the broccoli to it and boil for 4 to 5 minutes, drain.
Meanwhile, add bacon to a large saucepan and cook over medium heat until bacon is crisp. Use a slotted spoon to transfer bacon pieces to a small plate covered in a paper towel.
Add minced garlic to the bacon drippings and stir constantly for 1 minute, sprinkle in the flour and stir constantly for 1 more minute.
Gradually add the half and half and cook for 2 to 3 minutes until bubbly and thick while stirring constantly.
Reduce heat to low and add the cheese, stirring until it melts, then add the reserved pasta water and salt.
Add pasta and broccoli to the sauce, tossing to coat.
Plate and sprinkle with bacon, parsley, and black pepper.