Preheat the oven to 350°F (175C/165C Fan) and prepare donut moulds.
In a medium bowl, mix together the flour, baking powder, salt, cinnamon, nutmeg and clove.
In a large bowl, cream together the softened butter and sugar.
Add the eggs to the butter and sugar, one at a time, beating until incorporated. Add the vanilla. Then add the flour mixture slowly in a few additions.
Once dry ingredients are incorporated, pour the eggnog in, mixing continuously until the batter is well incorporated.
For filling the donut moulds, add the batter to a piping bag (or plastic bag) and fill around the moulds, until these are about ¾ full.
Bake in the centre of the oven for about 20 minutes, rotating halfway through. Once done, remove from the oven and leave to cool in the pan for a few minutes before carefully unforming and cooling completely on a wire rack.
For the glaze, place the icing sugar in a bowl and slowly whisk in eggnog, add slowly bit by bit until it reaches your desired consistency (a tablespoon or two). Dip the donuts into the glaze and top with a sprinkle of ground nutmeg.