Combine first 6 ingredients in a large bowl; make a well in center of mixture. Combine egg, yogurt, butter, and 1 tablespoon lemon juice; add to dry ingredients, stirring just until moistened. Spoon batter into greased muffin pans, filling three-fourths full.
Bake at 400° for 18 to 20 minutes or until golden. Cool in pans on a wire rack 5 minutes; remove from pans and place on wire rack. Prick muffins with a wooden pick. Combine 1/4 cup sugar, 2 teaspoons lemon rind, and 1/3 cup lemon juice in a saucepan. Cook over medium heat, stirring constantly, until sugar dissolves. Spoon glaze over warm muffins.