Preheat your oven to 350F and grease a 10-cup bundt pan.
Sift together the flour, baking powder, salt and nutmeg and set aside.
Using an electric mixer, cream together the sugar and butter until light and fluffy. Add the eggs one at a time and then the rum.
With the mixer on low speed, start adding the flour mixture, alternating with the eggnog, until both are incorporated into the batter.
Pour the batter into the prepared bundt pan and give the bottom of the pan a few hard taps on the counter to make sure the batter settles into the crevices of the bundt pan and air bubbles are released.
Bake for about 40 minutes, or until a tooth pick inserted into the centre of the cake comes out clean.
Let cool in pan for 10 minutes before turning out onto a wire rack to cool completely.
To make the glaze, stir together the powdered sugar, eggnog and nutmeg until smooth.
Pour over the cooled cake. Slice and serve.
Notes
I used a 10-cup bundt pan for this cake. If you use a larger bundt pan, the batter will not fill the pan. You'll also need to reduce the baking time.
Make sure you grease your bundt pan thoroughly, especially in the crevices (if your pan has a detailed design) so the cake doesn’t stick.
To ensure the butter and sugar cream together well, you'll need to bring the butter to room temperature. The eggs should also be at room temperature.
If you don't need this cake to be dairy-free, you can use dairy butter and traditional eggnog.
For the dairy-free eggnog, the recipe was tested with almond nog. Other types may work too, such as coconut nog, but I haven't tested them in this recipe.
For a non-alcoholic version, use rum extract instead of rum.
The glaze is a little thick. If you want it thinner, just reduce the amount of powdered sugar or add more eggnog.
Let the cake cool fully before adding the glaze. If the cake is warm, the glaze may melt into the cake.