Cook bacon till crispy. Drain excess grease. Set aside to cool on a plate lined with a paper towel. Break up into small bite-sized pieces when cool.
Dice your jalapeño peppers, or slice into rings.
In a medium pot, add pasta and cold water till it just covers the pasta.
Bring to boil, then reduce and cook (stirring frequently) till the pasta is just shy of al dente.
Add the evaporated milk, the cheeses, the butter and all the spices.
Cook till sauce thickens up. This can take 8-10 minutes depending on the pasta you are using. Keep an eye on the pasta, stirring frequently. Remove from heat when sauce is slightly thinner than you would like, as it does thicken more as it cools.
Serve immediately with bacon, diced jalapenos and a sprinkle of cayenne if desired. Add more salt and pepper to taste.