Place a large pot of water over high heat and bring to a boil
While the water is heating, shred the 8 ounces of white cheddar and cut 4 ounces of white American into small cubes and set aside for now
As soon as the water begins to boil, add a generous pinch of salt and cook your pasta according to manufacturer’s directions
While the pasta is boiling, place a pot over medium heat and add 4 tablespoons of butter
Once the butter has melted, whisk in 1/4 cup of all purpose flour and cook while whisking for about 60 seconds
Whisk in 1 1/2 cups of whole milk and 1 1/2 cups of heavy cream and season with a teaspoon of salt, 1/4 teaspoon of black pepper and the optional dijon mustard and hot sauce
Continue whisking until the mixture begins to simmer
As soon as it begins to simmer, reduce the heat to low and slowly add the cheese stirring as you go
As soon as the cheese has all been added and has fully melted, drain the cooked pasta and transfer it into the cheese sauce
Mix until the pasta is fully incorporated
Transfer the pot off of the heat and enjoy immediately or allow the pasta to rest for 10 minutes if a thicker consistency is preferred