Heat oven to 375 degrees F. Lightly spritz two cavities of a standard muffin tin with cooking spray. Place a slice of ham in each cavity and form into a cup.
Crack each egg into a ham cup. Sprinkle evenly with Parmesan cheese, scallion, salt and pepper.
Bake 15 to 20 minutes, or to desired doneness. If you prefer the yolk more runny, bake for less time (15 minutes). If you prefer the yolk more hard, bake longer (20 minutes). It may take some experimenting to get your eggs just right.