
Preheat oven to 400º F. Grease 12 3" x 1 ¼" muffin cups. In a large bowl, stir together flour, 2/3 cup sugar, baking powder, soda and salt. In another bowl, stir together butter, egg, yogurt, lemon peel and vanilla until well blended. Make a well in center of dry ingredients and add yogurt mixture. Stir just to combine. Spoon batter into prepared muffin cups. Sprinkle remaining 1 Tbsp. sugar on top of 12 muffins. Bake 20-25 minutes. Cool on wire rack 5 minutes before removing muffins from cups. Finish cooling on rack. They freeze well.