In a large mixing bowl, sift together the flour, baking soda, ground nutmeg, salt, and sugar.
Using a pastry blender, cut the butter into the dry ingredients until it is as fine as corn meal.
In a separate large mixing bowl, combine the buttermilk, vanilla extract, and slightly beaten eggs.
Add the dry ingredients to the liquid ingredients, mixing 'til you have a smooth cookie dough.
Cover the dough and chill in the refrigerator overnight, or at least 4 hours.
Pre-heat the oven to 425° F.
Turn the dough out onto a lightly floured surface, coating the dough with flour and kneading it until it's less sticky and more pliable.
Then roll the dough out to about a 1/4 to 1/2-inch thickness.
Cut out cookies with floured cookie cutters.
Place the cutout cookies on an un-greased cookie sheet, and bake at 425° F for about 8-10 minutes, or until the cookies begin to turn slightly golden.
Place the cookies on a wire rack to cool completely before decorating.