In a medium mixing bowl, whisk together the whole eggs, egg whites, Greek yogurt, sea salt, black pepper, and garlic powder until the mixture is smooth and well-combined.
Place a large non-stick skillet over medium heat and add the extra virgin olive oil.
Add the diced red onion and red bell pepper to the skillet, sautéing for 4 to 5 minutes until the vegetables are softened and the onions are translucent.
Add the baby spinach to the skillet and stir for about 1 minute until the leaves are just wilted.
Reduce the heat to medium-low and pour the egg mixture over the sautéed vegetables.
Using a silicone spatula, gently fold the eggs by pushing them from the outer edges toward the center, allowing the liquid egg to flow into the gaps to create soft, pillowy curds.
When the eggs are almost set but still slightly moist, sprinkle the crumbled feta cheese evenly over the top.
Continue to fold gently for another 30 seconds until the cheese is slightly warmed and the eggs are fully cooked.
Remove the skillet from the heat immediately and serve the scramble warm.