01 - Preheat oven to 350°F. Lightly grease a 12-cup muffin tin or line with silicone liners.
02 - In a skillet over medium heat, cook turkey sausage, breaking it up with a spatula, until browned and cooked through. Drain excess fat.
03 - Add bell pepper and spinach to the skillet. Sauté for 2–3 minutes until vegetables are softened. Remove from heat and cool slightly.
04 - In a large mixing bowl, whisk together eggs, milk, garlic powder, paprika, salt, and pepper.
05 - Add cooked sausage mixture, green onions, and shredded cheese (if using) to the eggs. Stir until thoroughly combined.
06 - Divide egg mixture evenly among muffin cups, filling each about three-quarters full.
07 - Bake in preheated oven for 20–25 minutes, or until muffins are set and lightly golden on top.
08 - Let muffins cool for 5 minutes in the pan before removing. Serve warm or cool completely for storage.