In a large bowl, cream the brown sugar, white sugar, eggs, and the shortening. Sift together the flour, baking powder, baking soda, cinnamon, and nutmeg. Alternate adding the buttermilk with the dry ingredients.
Roll dough into walnut sized balls and roll the balls in colored sugar if desired. Place them 2 inches apart on an unprepared cookie sheet. Bake for 10 to 13 minutes in the preheated oven. Remove to cool on wire racks.