Spray muffin tin with nonstick cooking spray.
Whisk the eggs, milk, pepper, and salt in a large bowl to blend well.
Stir in the ham, cheese and parsley.
Fill prepared muffin cups almost to the top with the egg mixture.
Bake until the egg mixture puffs and is just set in the center, ~15 minutes. The frittatas will collapse as they cool.
Using a rubber spatula, loosen the frittatas from the muffin cups and slide the frittatas onto a platter.
