Preheat oven to 375F°. Lightly spray a nonstick 6-muffin tin with oil spray.
Combine potatoes, 1/2 cup onion, garlic powder, salt and pepper. Fill each muffin tin with 1/4 cup of potatoes and press along the side of the tin so that it forms a nest.
Bake 35 minutes or until golden brown and edges are crispy.
While nests are baking, combine the egg whites with remaining ingredients in a medium bowl.
Remove nests from the oven when golden brown.
Fill each cup with about 3 tbsp of egg mixture. Return to the oven and bake an additional 17-20 minutes or until eggs are fully cooked.