Preheat your oven to 350°F and lightly grease a standard 6-cup muffin tin with avocado oil to ensure easy removal.
Heat a small skillet over medium heat and cook the ground turkey until fully browned, breaking it into small crumbles as it cooks.
While the turkey cooks, finely chop the baby spinach and dice the red bell pepper into small, uniform pieces.
In a large mixing bowl, whisk together the whole eggs and egg whites until the mixture is well-combined and slightly frothy.
Season the egg mixture with sea salt, black pepper, and garlic powder, then fold in the cooked turkey, spinach, and bell peppers.
Pour the mixture evenly into the prepared muffin cups, filling each about three-quarters of the way to the top.
Crumble the feta cheese over the top of each cup and bake for 20 to 25 minutes until the eggs are set and the tops are golden.