Prepare spaghetti according to package instructions. When draining pasta reserve½ c. pasta-water to use in the sauce.
Heat a deep skillet over moderate heat. Then add the sliced bacon and simmer for 5minutes, or till the bacon is crispy. Toss the garlic to the skillet & saute for a few minute.
Add the hot drained spaghetti then toss for a few minutes to coat the pasta with bacon-fat. Then remove pan from heat.
Beat parmesan and eggs together in a mixing-bowl. Then add mixture to the pasta, whisking till eggs thicken, but don't scramble.
Thin out the sauce with reserved pasta-water if desired. Season carbonara with black pepper. Garnish with parmesan cheese and parsley if desired.