Pre-heat the oven to 325°F.
In a large mixing bowl cream the butter and sugar until light and fluffy, approximately 5 minutes.
Add the eggs one at a time beating after each addition scraping down the bowl as needed.
In a medium bowl add, the gluten-free flour, baking powder, nutmeg and salt. Mix until combined.
Add the flour mixture to the batter alternately with the eggnog, starting and ending with the flour mixture.
Add the vanilla extract and mix until blended.
Let the batter rest for 20 minutes.
While the batter is resting, grease and flour a large bundt pan.
Pour the batter into the bundt pan (the batter will be very thick).
Bake for 1 hour 10 minutes, checking periodically starting at the 50 minute mark. Cake is ready when a tester inserted into the cake comes out clean.
Let the cake sit in the pan for 5 minutes before inverting onto a serving plate.
Let the cake cool completely then sprinkle with powdered sugar if desired.