Spray medium skillet with cooking spray. Add sausage; cook over medium heat 3 minutes, or until lightly browned, stirring occasionally. Add onions and garlic; cook 1 to 2 minutes, or until garlic is tender.
Beat Egg Beaters, milk, black pepper and red pepper in medium bowl with wire whisk until well blended; pour into skillet. Add sausage; cook until Egg Beaters are almost set; stir. Cook an additional 6 minutes, or until Egg Beaters reach desired doneness, stirring occasionally. Meanwhile, heat tomatoes in small saucepan over medium heat, stirring occasionally.
Spoon about 1/3 cup of the egg mixture over each muffin half; top with about 1 tablespoon tomatoes. Serve with hot pepper sauce, if desired.