Sift flour, soda, salt, nutmeg and powder in a bowl.
In separate bowl cream the butter and sugar (use cookie paddles or dough hook this will get thick)
Add the egg and beat again
then add the vanilla and sour cream and beat it smooth
Mix in dry ingredients and beat smooth - it will be thick.
wrap up in wax paper or parchment paper and chill in fridge for 3-4 hours
preheat oven to 350
roll out to 1/4 inch and cut holiday shapes
bake for 8-10 mins, until the edges get a slight golden color to them (don't over bake) let cool
Icing
Mix butter, powdered sugar, milk, vanilla and peppermint in your mixer.
it will be thick at first - great for spreading
thin with milk to get a "toothpaste" thickness good for piping - great for outlining cookies
thin more to create a icing you can fill in "color flow' style for a smooth finish. The perfect thinness is when stop stirring the icing and count to 10 it gets smooth.