In a bowl, beat eggs, and stir in baby spinach and Parmesan cheese. Season with onion powder, nutmeg, salt, and pepper. In a small skillet coated with cooking spray over medium heat, cook the egg mixture about 3 minutes, until partially set. Flip with spatula, and continue cooking 2 to 3 minutes. Reduce heat to low, and continue cooking 2 to 3 minutes, or to desired doneness.