Preheat your oven to 375°F and lightly grease a small oven-safe baking dish with a mist of oil.
Heat the olive oil in a skillet over medium heat. Add the diced red onion, zucchini, and red bell pepper, sautéing for 5-6 minutes until tender-crisp.
Add the baby spinach to the skillet and stir for 1 minute until just wilted, then remove the pan from the heat.
In a blender or food processor, combine the whole eggs, egg whites, cottage cheese, sea salt, black pepper, and garlic powder. Pulse until completely smooth and creamy.
Transfer the sautéed vegetables into the bottom of the prepared baking dish, spreading them out into an even layer.
Pour the blended egg mixture over the vegetables and sprinkle the crumbled feta cheese evenly across the top.
Bake for 25-30 minutes, or until the center is set and the edges are lightly golden brown.
Allow the bake to cool for 5 minutes before slicing and serving.