Heat 1 tablespoon butter in a large skillet over medium heat (or omit the butter and use a non-stick skillet sprayed with cooking spray) add in spinach and cook stirring until spinach wilts, remove to a bowl.
Add in chopped bacon; cook until crisp (about 3 minutes) remove the bacon to the plate with the spinach; set aside (reserve about 1 tablespoon bacon fat in the skillet).
Add in onion to the drippings and cook for about 3 minutes or until softened.
Add in garlic and chili flakes; cook stirring for 2 minutes.
Add in wine and drained diced tomatoes; cook stirring over medium heat for about 3-4 minutes, then remove the skillet from heat.
Cook the spaghetti until al dente (omitting any salt and fat to the pot); Drain well then immediately add the cooked spaghetti to the skillet.
Add in the spinach and bacon; stir well to combine, then place the skillet over low heat.
In a small bowl combine the eggs with 1/2 cup Parmesan cheese; add to the pasta; cook over low heat tossing for 1-2 minutes.
Season with fresh ground black pepper to taste and salt if desired.
Remove from heat sprinkle the top with fresh parsley.