In a large pot, boil 1 pound of macaroni or other pasta until al dente. Drain and run cold water over the pasta to stop the cooking process (the pasta will cook more when we add it to the oven to broil). Set aside
Set oven to "broil". Lightly grease a 9x13 inch baking dish. Set aside
Take your 6 strips of bacon and chop into bite sized pieces. In a large pot, add the bacon and cook until crispy
Remove bacon pieces and set aside to drain on a plate with a paper towel. Reserve bacon grease in the pot. Add 2 tbsp of flour to the pot and whisk until light tan (see alternative instructions in "Notes" section if you are not using bacon)
Add in milk, salt, and pepper and whisk until thick enough to coat the whisk (about 4 minutes)
Add the pureed squash and cream cheese to the pot. Stir for about 2 minutes until all ingredients are combined. Add in 2 cups of the white cheddar. Stir until melted.
To your pot, add in the pasta and 1/2 cup of salsa. Stir until well combined.
Transfer mac and cheese to a 9x13 inch baking pan. Sprinkle top with 1 cup of remaining white cheddar cheese and breadcrumbs if desired.
Broil for 3-5 minutes, or until cheese is melted and the breadcrumbs are golden brown. Serve alongside a nice, green salad for a well balanced meal!