Cook the bacon in a skillet over medium heat until crisp.
Remove from the skillet and place on a paper towel to drain. Chop into bits.
Cook the elbow macaroni to al dente - don't overcook (it will continue to cook in the cheese sauce), per package instructions.
One minute before the timer goes off for the pasta, throw the broccoli florets into the boiling pasta water; cook for 1 minute.
Drain the pasta and broccoli well.
While the macaroni cooks, melt the butter over medium heat in a saucepan; stir in the flour until well combined and cook for 30 seconds, whisking constantly.
Very slowly add in the milk, whisking constantly, until well combined; cook and stir until bubbly.
Reduce heat to low and add the cheddar cheese, American cheese, and grated Parmesan cheese; stir until melted. Season with sea salt and freshly cracked pepper, to taste. Add the cooked & drained noodles and broccoli florets to the sauce. Toss to coat evenly then turn the stove off and let it sit for 3-5 minutes to allow the sauce to thicken. Stir, taste & re-season, if needed. Sprinkle the bacon bits on top. Serve immediately. Enjoy.