PREPARATION:

1. Preheat oven to 400°F. Coat twelve medium-size muffin cups with nonstick cooking spray, or line with paper liners; set aside.
2. Combine flour, baking powder, baking soda, salt and orange peel in medium bowl. Combine egg, orange juice, butter, milk and vanilla in small bowl until blended; stir into flour mixture just until moistened.
3. Spoon batter into prepared muffin cups, filling each cup 1/2 full. Bake 18 to 20 minutes or until golden brown. Let cool in pan on wire rack 5 minutes. Remove from pan; cool. Serve warm or at room temperature. Spread with whipped butter and marmalade, if desired.