Preheat oven to 400°F and line a rimmed sheet pan with parchment paper.
Dice the bell peppers and red onion into small, uniform pieces.
Place the peppers, onions, and ground turkey on the sheet pan, drizzle with olive oil, and season with sea salt, black pepper, and garlic powder.
Roast for 10 minutes until the turkey is cooked through and vegetables are slightly softened.
In a medium bowl, whisk together the large eggs and egg whites until well combined.
Remove the pan from the oven, toss the baby spinach with the roasted mixture, and spread everything evenly across the pan.
Pour the egg mixture over the vegetables and turkey, ensuring even coverage.
Return the pan to the oven and bake for 8 minutes until the eggs are set and slightly golden on the edges.
Slice into squares and serve immediately.