Line a 9x5 loaf pan with parchment paper and preheat your oven to 350 degrees F.
In a large bowl, mix the flour, baking soda, baking powder, cinnamon, and salt.
In a separate bowl, cream the butter, sugar, and vanilla extract using an electric mixer. Mix until smooth and creamy.
Add the flour mixture and eggnog to the butter mixture and mix until well combined.
Add the batter to the prepared pan and smooth the top with a spatula.
Bake for 50-55 minutes or until a toothpick inserted in the center comes out clean. Take the eggnog bread out of the pan and let it cool on a wire rack.
While the bread cools, prepare the glaze. Simply mix the powdered sugar and 3 tbsp eggnog. Mix well.
Pour all of the glaze over the bread and enjoy!
Notes
If the glaze is too runny, add more powdered sugar.