Prick sweet potatoes with a fork and rub all over with olive oil, salt and pepper. Bake at 400 degrees for 50-60 minutes until just tender.
While the sweet potatoes are baking, brown the Italian sausage over medium high heat. Remove to a paper towel lined plate leaving just a little grease behind.
Add the onion and sauté a minute or so, until translucent. Add the apple, sage, salt and pepper and continue sautéing until everything is softened and fragrant, about 5-7 minutes.
Return sausage to the mixture and deglaze the pan with a big splash of white wine, if using, scraping up all the flavorful browned bits.
Slice the sweet potatoes open, add a big scoop of filling and top with cheese. Return to the oven for a few minutes until the cheese is melted.
Garnish with fresh parsley and/or balsamic glaze!
