Preheat oven to 400 degrees F. Coat a large rectangular baking dish with nonstick cooking spray.
Trim off the stem ends of the zucchini and cut each zucchini in half lengthwise. Use a spoon to carefully scoop the center flesh out.
Heat a large pan or skillet on medium-high heat and add olive oil and onions. Let cook until onions are translucent, then add ground turkey meat.
Add rice, salsa, garlic powder, cumin, chili powder, salt, and pepper. Let the meat for 4-5 minutes until completely cooked through.
Divide the cooked taco meat equally into the hallowed cooked zucchini boats. Press the meat firming into the boats with a spoon. Cover with foil and bake for 25 minutes.
Remove the foil and top with shredded cheese, place back in the oven until the cheese is melted, about 5 minutes.