In large bowl, beat granulated sugar and softened butter on medium speed about 3 minutes or until light and fluffy. Add eggs, one at a time, beating on medium speed 1 minute after each addition. Beat in sour cream, lemon peel and 2 tablespoons lemon juice until smooth. Gradually beat or stir in dry mixture (dough will be thick). Divide batter evenly among muffin cups. Smooth tops of batter in cups with wet fingers.