In a medium-sized mixing bowl, whisk together the large eggs, liquid egg whites, sea salt, black pepper, and garlic powder until the mixture is completely uniform.
Place a large non-stick skillet over medium heat and add the avocado oil, tilting the pan to ensure the surface is evenly coated.
Add the fresh baby spinach to the skillet and sauté for approximately 1 minute until the leaves are wilted and bright green.
Pour the egg mixture into the skillet directly over the spinach, allowing the eggs to sit undisturbed for 30 seconds to begin setting.
Using a silicone spatula, gently push the eggs from the outer edges toward the center, creating large, fluffy curds.
When the eggs are mostly set but still look slightly moist, sprinkle the crumbled feta cheese over the top and gently fold it in.
Remove the skillet from the heat immediately and serve the scramble alongside a warm slice of toasted sprouted grain bread.