Preheat your oven to 350 degrees.
Put the peppers in a large microwave safe bowl. Spray liberally with cookign spray. Cover the bowl with a microwave safe plate and microwave for 7 minutes (see note)..
While the peppers are cooking in the microwave, heat a large skillet over medium heat. Add the olive oil and then add the onions. Cook the onions for approximately 7 minutes or until very soft.
Add the garlic and saute for another minute.
Add the ground turkey, breaking it up as you cook it. Add in the Italian seasoning, salt, pepper, and cumin.
Once the turkey is compltely cooked through, stir in the spaghetti sauce, 1 cup of the mozzarella cheese, and cooked rice.
Put the peppers on a parchment lined baking tray, discarding any liquid that might have accumulated during microwaving. Divide the filling mixture amonst the eight pepper halves and then top with remaining cheese.
Bake the peppers for 15 to 20 minutes until the cheese completely melts and begins to bubble.