Preheat oven to 400 degrees F. Grease muffin tin. In large mixing bowl combine first 3 ingredients. In separate small bowl, blend together sour cream and eggs. Stir into dry mixture. Divide batter among muffin cups. Let rest at room temperature 5 to 10 minutes.
Bake 18 to 20 minutes, until tester inserted in center comes out clean and center of muffin springs back when touched. Let muffins cool in pan 2 to 3 minutes. Remove from pan and transfer to cooling rack. Serve warm.