Preheat your oven to 375 and spray a mini muffin pan with cooking spray.

In a large bowl, mix together the flour, granulated sugar, baking powder, and baking soda.

Whisk together the egg and eggnog. Then add the butter.

Gently fold the egg/eggnog/butter mixture into the dry ingredients.

Spoon into the mini muffin tin and bake for 8 to 10 minutes. (All ovens are different, but mine were underdone at 8, overdone at 10, and perfect at 9 minutes.)

While the muffins are cooking, make the glaze. Mix together the powdered sugar, rum, cinnamon, and 2 tablespoons of eggnog.

When you bring the muffins out of the oven, let them cool until they won't burn your fingers, dip them in the glaze, and set them on a wire rack.