Heat oven to 350 degrees.
Spray a 12 cup muffin pan very well with non-stick spray.
Whisk together the eggs, half and half, salt and pepper in a medium bowl.
Evenly distribute the egg mixture among the muffin cups.
Add about 2T of desired mix-ins and sprinkle with parmesan cheese.
Bake the frittatas until they are puffy and edges are golden brown, about 20-25 minutes. (If necessary, run a butter knife around the edge of each one to loosen before removing from the pan)
*Great to use for sleep-overs or to accommodate “picky” eaters in the family!