Preheat oven to 400F. In a mixing bowl, whisk together flour, baking powder, baking soda, salt, cinnamon and nutmeg. Set aside. In a separate bowl, whisk together milk and buttermilk. Set aside.
In a large mixing bowl, blend together butter and sugar until well combined—about 30 seconds. Mix in eggs one at a time. Blend in vanilla.
Using a wooden spoon to mix, add flour mixture in three separate batches, alternating with two additions of milk, mixing just until combined after each addition—batter will be thick.
Divide among lined muffin cups. Bake for 15 minutes. Transfer to a wire rack and allow to cool for about 10 minutes.
During the last few minutes of cooling, prepare the glaze by whisking together ingredients. Dip each muffin in glaze while twirling and rotating to evenly coat the tops. Lift and allow the excess to run off. Enjoy warm or allow to rest at room temperature for 10 minutes until the glaze has set. Store in an airtight container.