Preheat oven to 425F. Line twelve 1/3-cup muffin cups with paper or foil liners. Stir first 6 ingredients in large bowl to blend. Whisk buttermilk, butter and egg in medium bowl to blend. Add to dry ingredients and stir just until combined. Fold in grated cheddar cheese. Divide batter equally among prepared muffin cups. Bake muffins until tops are golden and tester inserted into center comes out clean, about 20 minutes. Cool in pan on rack 10 minutes. Serve warm or at room temperature.