In a large bowl, add sausage, red bell pepper, yellow onion, eggs, garlic cloves, garlic powder, red pepper flakes, and salt and pepper. Whisk until well combined.
Use a ladle to pour mixture into 8-10 muffin tins. (I used a silicone muffin tray and did not have to grease it. If you are using a regular metal pan, thoroughly grease all of it or use muffin liners.
Place in oven and bake for 35-40 minutes or until cooked through.