• Preheat oven to 350 degrees F.
• In a large mixing bowl, cream together the butter and sugar until light and fluffy—about 3 minutes.  Slowly add the eggs one at a time and mix. In a separate bowl, combine the flour, cream of tartar, baking soda, salt, cinnamon, and nutmeg and mix, then add this to the butter mixture.
• In a small bowl, combine 1/4 cup sugar and 1 teaspoon cinnamon. 
• Scoop and roll the cookie dough into 1¼" balls and drop the cookie dough balls into the cinnamon and sugar mixture.
• Place 12 dough balls on a baking sheet about 3" apart. Bake at 350 degrees for 9-11 minutes, or until just golden on the edges.  
• Take the cookie out of the oven and let them cool for 2 minutes on the baking sheet.  Transfer the cookies to a wire rack and let them rest until they are completely cooled. 

Eggnog Buttercream Frosting

• With an electric mixer, beat 1/2 cup butter until it is light and fluffy.  
• Add the cinnamon, nutmeg, and powdered sugar.  mix until the butter and powdered sugar mixture resemble small peas. Slowly add the eggnog while mixing with the electric mixer.  Beat until light and fluffy. 
• Spread the eggnog buttercream frosting on the sugar cookies and add sprinkles if desired.  Enjoy!