In a large bowl add the flour, sugar, baking soda, baking powder, and salt; whisk well to combine. In a separate bowl add the eggs and lightly beat them with a whisk. Add in the eggnog and vanilla and beat until well combined. Stir the eggnog mixture into the dry ingredients, stirring just until everything is combined.
Pour batter by 1/3 cupfuls onto a buttered hot pan or griddle, adding only a few at a time so that they do not blend together. Cook for about 2 minutes - or until small bubbles form on top -before flipping them over. Cook on the second side until golden brown, about 1-2 minutes. Repeat with all pancake batter. Serve pancakes warm, with syrup and confectioners' sugar.