In a large pot, bring 3 - 4 quarts of water to a full rolling boil. Cook the pasta according to box directions. (My pasta took 6 minutes to be perfectly firm and fully cooked.) When the pasta is 2 minutes from being al dente, add the spinach to the pot with the pasta, thendrain the pasta/spinach and return to thepot.
While the pasta water is boiling and the pasta is cooking, fry the bacon in a large skilletover medium high heat.
When the bacon is fully cooked, remove from the pan and place on a paper towel to drain and then chop when cooled.
To the same skillet with the bacon fat, stir inthe flour with a whiskand turn the heat to medium. Once the flour has 'melted' into the bacon fat, slowlypour the milk into the skillet, whisking constantly. Continue to whisk the mixture constantly until it begins to bubble, then reduce the heat to low/simmer.Add the chunks of cream cheese and whisk until smooth. Stir in the shredded cheese and whisk until melted.
Pour the cheese sauce over pasta/spinach mixture, then stir in the chopped bacon. Add a little on top like I did in the photos, if you desire!
Serve Homemade Mac & Cheese with Bacon & Spinach warm out of the skillet.