In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs, one at a time, then stir in the vanilla extract and eggnog.
In a separate bowl, sift together the flour, baking powder, nutmeg, baking soda, cinnamon, cloves, allspice, and salt. Stir the dry ingredients into the wet mixture until just blended.
Fold in the walnuts. Drop by rounded teaspoonfuls onto ungreased cookie sheets.
Bake for 8 to 10 minutes in the preheated oven, until lightly browned. Allow cookies to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Interesting Facts
Eggnog is a traditional holiday drink made of milk, eggs and sugar.
Walnuts are a healthy source of protein and antioxidants.
Ground nutmeg and cinnamon are used in many holiday recipes, including eggnog cookies.