Preheat the oven to 400℉/204℃. Line a baking sheet with parchment paper or a silicone mat.
Scrub and wash the skin of the carnival squash, then pat dry. Slice each squash in half lengthwise. If they are difficult to cut, consider slicing off a little from the bottom and top so they can stand up straight on the cutting board. Then, use your palm to guide the knife blade through the squash. Scoop out the seeds from each half and discard.
Rub the cut sides of the squash with olive oil. Place cut side down on the baking sheet. Roast for 35 to 45 minutes until the flesh is tender and you can easily pierce the skin with a fork. Flip the halves over so they are cut side up.
While the squash is roasting, prep the filling. Warm 1 tablespoon of olive oil in a large skillet. Add the turkey sausage and cook, using a spoon to break it up as needed, until browned and cooked through, about 8 minutes. Transfer the cooked sausage to a plate.
In the same skillet, warm the other tablespoon of olive oil. Add the garlic, onion, apple, cranberries, kale, and sage. Cook for 7 to 10 minutes until the produce is softened. Remove from heat. Stir in the ½ cup cubed cheddar cheese and cooked turkey.
Spoon the stuffing into the squash halves, dividing it evenly among them. Pile it high on top. Then, sprinkle each one with the remaining grated cheese.
Pop the stuffed squash back in the oven for about 5 minutes until the cheese is melted. Enjoy warm!
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