Preheat your oven to 350°F (175°C). Grease and flour the 9x5 inch loaf pan or line it with parchment paper.
In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, salt, nutmeg, and cinnamon until well combined.
In a medium mixing bowl, beat the eggs. Add the eggnog, melted butter, and vanilla extract, then mix until combined.
Pour the wet ingredients into the dry ingredients. Gently fold together using a spatula or wooden spoon until just combined. Be careful not to overmix; some lumps are okay.
Pour the batter into the prepared loaf pan, smoothing the top with the spatula.
Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and let the bread cool in the pan for about 10 minutes. Then transfer the bread to a wire rack to cool completely before slicing.