Heat a large skillet over med-high heat and cook turkey, about 8-10 min, breaking it up with a wooden spoon to avoid oversized clumps. Remove turkey from skillet, then wipe down skillet with a paper towel. Add butter and cook onion, celery, and apple until tender. In a large mixing bowl, add turkey, veggies, cornbread stuffing, scooped out butternut squash, chicken broth, and eggs. Mix until well incorporated.