Preheat your oven to 350°F and generously grease six wells of a standard muffin tin with olive oil.
Finely chop the baby spinach and dice the red bell pepper into small pieces.
Slice the chicken sausage into small rounds or quarter-inch cubes.
In a large mixing bowl, whisk together the whole eggs, egg whites, sea salt, black pepper, and garlic powder until well combined and slightly frothy.
Distribute the chopped spinach, diced peppers, and chicken sausage evenly among the six prepared muffin cups.
Pour the egg mixture over the fillings in each cup, filling them about three-quarters of the way to the top.
Bake for 20 to 25 minutes or until the muffins have risen and the centers are firm to the touch.
Allow the muffins to cool in the tin for 5 minutes before using a silicone spatula to gently pop them out and serve.