Pierce the sweet potatoes all over with a fork. Cook in the microwave on HIGH until tender when pierced with a fork, 4 to 5 minutes per side. Let the potatoes rest until cool enough to handle.
Cut the potatoes in half lengthwise. Carefully scoop the flesh out of the potatoes and place in a medium-sized bowl. Reserve the skins. With the back of a fork, mash the potato flesh until most lumps are gone. Stir in the olive oil, ½ teaspoon cumin, ¼ teaspoons salt and ¼ teaspoon pepper. Divide the mashed sweet potato evenly between the potato skins. Place on a baking sheet.
Heat a large nonstick skillet over medium-high heat. Lightly coat with cooking spray. Add the ground turkey and cook, breaking up with a wooden spoon, until cooked through. Stir in the garlic, chili powder, remaining ¾ teaspoon cumin, oregano, paprika, and remaining ⅛ teaspoon salt and pepper. Cook for 1 minute. Stir in the crushed tomatoes.
Preheat the broiler. Spoon the turkey mixture into each sweet potato skin. Top each with 1 tablespoon grated cheese. Broil until the cheese is melted, about 30 seconds. Garnish with parsley. Serve.