In a large bowl, combine the flour, sugar, baking powder, baking soda and salt. In another bowl, beat the yogurt, egg, butter, lemon peel and lemon juice until smooth; stir into dry ingredients just until moistened.
Fold in the coconut. Fill greased muffin cups two-thirds full.
Bake at 400°F for 18-22 minutes or until golden brown and muffins test done. Cool for 5 minutes before removing from pan to wire rack.
In a saucepan, combine the lemon juice and sugar; cook and stir until sugar is dissolved.
Stir in coconut. Using a toothpick, poke 6-8 holes each muffin.
Spoon the coconut mixture over muffins.
Serve warm or cool to room temperature.
We have found we prefer them cooled as the lemon flavor isn't as overwhelming once they reach room temperature.