In a stand mixer, cream together the butter and the sugar. (3-4 minutes)
Add in the eggs and sour cream and mix well
Mix in the flour, baking soda, salt, and vanilla.
Let the dough chill in the refridgerator for 5 hours minimum, or overnight.
Roll the dough to ¼ in thick on a floured surface (don't be shy of the flour) and use cookie cutters to cut out shapes
Bake at 350° for 10 minutes.
Let the cookies cool completely before frosting.