In a large frying pan fry sausage over a medium heat until no longer pink. Add in celery and apples. I love the taste of Fuji apples and this is what I used but you can use any flavor apple you like. Now continue to cook this mixture for another five minutes for so to soften the apples and celery and combine all the flavors into all the ingredients. Add bread crumbs and cheese. mix all together well. Scoop mixture into each acorn squash. Bake for 30 minutes.