1Heat oven to 400°F. Grease bottoms only of 12 regular-size muffin cups with shortening or spray, or line with paper baking cups. In small bowl, mix all filling ingredients until smooth; set aside.
2In large bowl, beat milk, oil and egg with fork or wire whisk. Stir in remaining muffin ingredients just until flour is moistened. Divide batter evenly among muffin cups.
3Place about 1 rounded teaspoon filling on batter in each muffin cup. Top with remaining batter.
4Bake 20 to 25 minutes or until golden brown. Immediately remove from pan to cooling rack (may need to run knife around side of muffins to loosen). Cool 5 minutes. Serve warm or cool.