While pasta is cooking saute bacon in a medium skillet over medium-low heat until bacon is brown and crispy. Pour off half the excess bacon fat from the pan. Add the leftover edamame and saute for 2 minutes. Add cooked pasta, season with salt and pepper and stir so that the pasta is thoroughly coated with the bacon fat. Transfer to serving bowl and top with Parmesan cheese, if desired.
Heat oil in a large skillet over medium heat. Add onions and garlic, season with salt and pepper, to taste and saute for 2 minutes. Add edamame and saute for 4 minutes until edamame are heated through and onions are tender.