Preheat oven to 375F. In a large bowl, beat the sugar and wet ingredients until smooth. Add in the baking powder and spices and beat again, then gradually add the flour 1/2 cup at a time, beating between additions. When all the flour is incorporated, lightly spray a muffin tin with oil (or use liners) and spoon the batter into the pan. Bake for 22-25 minutes.
Melt the butter in a microwave safe bowl and stir in the other ingredients until combined. Remove muffins from oven and let them cool for 20 -30 minutes before glazing and serving. Refrigerate in an airtight container for up to a week.