Preheat oven to 375°F and lightly grease a small baking dish.
In a skillet over medium heat, add olive oil and sauté the diced onion and bell pepper until softened.
Add the ground turkey sausage to the skillet, breaking it apart with a spatula, and cook until browned and cooked through.
Stir in the fresh baby spinach and cook just until wilted, then remove from heat.
In a medium bowl, whisk together the eggs, egg whites, sea salt, black pepper, and garlic powder.
Transfer the sausage and vegetable mixture into the prepared baking dish, spreading it evenly.
Pour the egg mixture over the sausage and vegetables, ensuring everything is submerged.
Bake for 20-25 minutes or until the center is set and the edges are golden brown.