Preheat the oven to 375 degrees. Coat a 12-cup muffin tin with nonstick cooking spray.
Whisk the egg substitute, milk, pepper, and salt in a large bowl to blend well. Stir in the ham, spinach, cheese, and parsley.
Fill prepared muffin cups almost to the top with the egg mixture. Bake until the mixture and is just set in the center, about 8 to 10 minutes.
Loosen the frittatas from the muffin cups with a rubber spatula, and slide them onto a platter. Serve warm.