Preheat oven to 400℉ (200°C) Line a baking sheet with greased parchment paper. Cut the acorn squash in half from tip to stem. Remove the seeds with a spoon. Drizzle a little olive oil and half the salt & pepper over the squash. Place the squash on the parchment-lined baking sheet, flesh side up. Roast in the oven for 40 minutes - 1 hour, until it is easily pierced with a fork. Cook time will vary depending on the size of your squash.
While the squash is baking, finely chop the onion, apple, and celery. Heat 1 tablespoon of olive oil in a pan or skillet over medium heat. Add the onions, apple, and celery and cook until softened, about 5 minutes.
Add the minced garlic, fresh thyme, and fresh rosemary and mix until fragrant, about 30 seconds.
Add the ground turkey, salt, and pepper to the pan and break apart the meat with a wooden spoon. Cook until the meat is brown, about 5-7 minutes.
Add the chicken broth and let it simmer another 1-2 minutes to let the liquid absorb.
Turn off the heat and add half the cheese and dried cranberries. Mix to combine until the cheese is melted.
When the acorn squash is fork tender, remove it from the oven and fill the squash bowls with the turkey stuffing. Top with the rest of the cheese.
Put the stuffed squash back in the oven for about 5 minutes or until the cheese is melted. If you want to brown the cheese, broil them for 2-3 minutes.
Hint - if you're looking to prep ahead, you can chop the onion, apple, celery, thyme, and rosemary & mince the garlic ahead of time. You can also roast the acorn squash ahead of time.