In a small saucepan, combine 1/4 cup sugar, orange zest and water. Cook and stir over low heat for 3-5 minutes or until sugar is dissolved. Add butter; stir until melted. Remove from the heat; set aside.
In a large bowl, combine the flour, baking powder, baking soda, salt and remaining sugar. In another bowl, whisk the eggs, yogurt, milk and reserved butter mixture. Stir into dry ingredients just until moistened.
Coat muffin cups with cooking spray; fill each with a scant 1/4 cup of batter. Bake at 375° for 13-18 minutes or until a toothpick comes out clean. Combine glaze ingredients; spoon about 1-1/2 teaspoons over each warm muffin. Remove from pans to wire racks.