Preheat your oven to 400°F and pierce the Russet potato several times with a fork.
Bake the potato directly on the oven rack for 45-50 minutes until the skin is crisp and the inside is tender.
While the potato bakes, brown the ground turkey in a non-stick skillet over medium-high heat until fully cooked through.
Season the turkey with sea salt, black pepper, and garlic powder, stirring well to incorporate the spices.
Add the fresh spinach to the skillet and sauté for 1-2 minutes until the leaves are just wilted.
Remove the baked potato from the oven and slice it in half lengthwise.
Carefully scoop out the potato flesh into a mixing bowl, leaving a thin shell to maintain the boat shape.
Mash the potato flesh with the non-fat Greek yogurt until the mixture is smooth and creamy.
Fold the cooked turkey and spinach mixture into the mashed potatoes until evenly distributed.
Stuff the filling back into the potato shells and top each half with the sharp cheddar cheese.
Place the boats under the broiler for 2-3 minutes until the cheese is melted and bubbling.
Garnish with sliced green onions and serve immediately.