Cream soft butter. In another bowl, beat eggs & yolks and whisk until blended, add 1/2 c cheese.
Heat large casserole dish in 2 degree oven. Bring water and salt to boil in large pot. Meanwhile, fry bacon in skillet over medium heat until crisp. Pour off half of fat and stir in red pepper flakes and cream. Bring cream mixture to simmer and keep warm until spaghetti is done.
Transfer cooked spaghetti to heated casserole dish and stir in creamed butter. Coat well. Stir in hot bacon and cream mixture and finally the beaten eggs and cheese. The heat of the pasta will cook the raw eggs. Taste and season with salt and pepper. Serve with remaining grated cheese.