Heat a skillet on medium heat. Separate the yolks from the eggs and place in a medium sized bowl. Measure out all ingredients.Tip - Egg whites are freezable! Save them for an omelet for another day!
Cut the bacon into quarter-inch pieces before frying, or crumble/chop the bacon after frying.I found that cutting it before frying gave me the exact crispy texture desired.
If using hard or frozen pasta, cook per the package instructions.
Fry the bacon
Add the bacon and fry crispy. Remove the bacon and let it drain on a paper towel.
Saute the noodles
Reduce the heat to medium low and add the butternut squash noodles into the skillet with the bacon fat. Cover and let cook 4-5 mins. Stir once or twice.
Remove the noodles and set aside. Remove the skillet from the heat and reduce to the lowest heat.
Make the sauce
Add the cream, salt, pepper and cheeses to the skillet (still removed from the heat). Let it warm. If it begins to boil or pop, remove it from the heat.Have a cup of cold water on standby.
After it has warmed for 2 mins, SPOON the cream into the bowl with the yolks and MIX AFTER EACH SPOONFUL. This is called tempering - gradually raising the temperature of the yolks to the temperature of the cream so they don't scramble.
When you've mixed all of the cream with the yolks, return the mixture to the skillet and place back on the low heat. Cook for 1-2 mins.If you see any chunk or texture in the sauce, immediately remove from the heat. Add 1 Tbsp of water and stir. Do not scrape the bottom when stirring.The yolks have to cook for 2 mins, so return to the heat if necessary.
Add the noodles and toss to coast them with the sauce.