In a large bowl, cream together butter and both sugars. Add eggs and mix well. Add vanilla and eggnog and mix again.
In a medium bowl, combine flour, baking powder, salt, cream of tartar, cinnamon, and nutmeg.
Add the dry ingredients to the wet ingredients and mix until well combined.
In a small bowl, combine the cinnamon and sugar topping. One at a time, drop rounded tablespoons of cookie dough into the cinnamon sugar and roll the dough ball until it is completely covered with the mixture.
Bake on a parchment lined baking sheet for 10-13 minutes or until the cookies are lightly golden.
Allow the snickerdoodles to cool on the baking sheet for 10 minutes.