This recipe is a family favorite of my siblings. It is one of the comfort foods my mom makes when they return home for a visit.
This creamy pasta is an Italian tradition. With its modest ingredients, it is a “What do I have in the kitchen to make for dinner tonight?” kind of throw-together meal.  
You can substitute heavy cream for the milk if you prefer an extra rich and creamy pasta. 
4 Tbsp butter, softened
2 whole eggs
2 egg yolks
1½ cup parmesan cheese, finely grated
1 lb. spaghetti, or gluten-free spaghetti
8 slices of bacon, cut crosswise into ¼ inch strips
1 tsp red pepper flakes
½ cup low-fat milk
2 Tbsp Italian parsley, finely chopped (optional) 
Heat the oven to 200℉
In a small bowl, cream together the butter with a wooden spoon until soft and fluffy and set aside. In a second small bowl, beat the eggs and the yolks with a whisk until they are well blended. Then stir in a ½ cup of grated cheese and set aside. 
Place a large ovenproof serving bowl or casserole dish in the oven to warm. At the same time, boil water in a large stockpot. Drop the spaghetti into the boiling water and stir to ensure the strands do not stick to one another or the bottom of the pot. Cook the spaghetti over high heat for 7 - 12 minutes, or until tender.
While the spaghetti is cooking, fry the bacon pieces in a large skillet on medium-high heat until crisp. Pour off half of the bacon fat and stir the red pepper flakes and the milk into the pan. Bring the sauce to a simmer and keep warm until the spaghetti is done. 
When the spaghetti is done, drain it thoroughly in a large colander, lifting the noodles with two forks to ensure all the water runs off. Transfer the spaghetti to the heated serving bowl and stir in the creamed butter, tossing and turning the noodles with two forks to coat every strand. Next, stir in the bacon and milk mixture and finally the beaten eggs and a ½ cup cheese, mixing everything thoroughly. The heat of the pasta and other ingredients should cook the raw eggs on contact. Taste and season with salt and pepper and garnish with parsley. Serve the carbonara immediately with the remaining ½ cup cheese on the side. 
Just Salt It, and enjoy!