Melt the butter in a large saute pan and cook the bacon in it for about 3 minutes.Add the snow peas and tomatoes and cook for 3 – 5 minutes, or until the tomatoes are starting to pop.Stir in the scallions, parsley and lemon zest and remove from the heat.Fold in the spaghetti squash and parmesan cheese until well distributed.Season with salt and pepper to taste.Serve garnished with more parsley and parmesan if desired.