1 c butter, softened

1 c sugar

1 egg, separated

2 c flour

2 1/2 t cinnamon

red and green sugar crystals (or whatever colors you want to use)

Cream butter, sugar and egg yolk.  Add flour and cinnamon (I usually add just a little extra) and mix well.  Roll the dough out into 3/4" – 1" balls.  Dip the tops in the egg white, then sugar crystals and place them on a cookie sheet.  Press them down a little on the cookie sheet to they don't roll over when they're baking.  Bake at 350 until the bottoms are lightly browned.  

These are loads of fun for kids.  My brother and I always loved to roll out the little balls and decorate them when we were little – I would be in charge of making the red cookies, and he would do the green ones.  I have also shaped the dough into little heart shapes and just used red crystals for Valentines day.