6 servings (serving size: 2 "muffins")
Preheat oven to 350°.
Heat the olive oil in a large nonstick skillet over medium-high heat. Add chopped onion, chopped carrot, dried oregano, and minced garlic; sauté 2 minutes. Cool.
Combine onion mixture, 1/2 cup ketchup, and the remaining ingredients except cooking spray in a large bowl.
Spoon the meat mixture into 12 muffin cups coated with cooking spray. Top each with 2 teaspoons ketchup. Bake at 350° for 25 minutes or until a thermometer registers 160°. Let stand for 5 minutes.