Cream together butter, cream cheese, and sugar.
Add egg yolk, vanilla, and orange rind.
Slowly add flour, cinnamon, and salt. Mix well.
Place in fridge for several hours (until firm) or overnight.
Preheat oven to 350 degrees.
Press dough onto cool ungreased cookie sheet.
Add sugar decorations as desired.
Bake at 350 degrees for 12-15 minutes. Edges will just start to turn brown.
UPDATE: I forgot to mention that this is easily doubled or even tripled and the dough keeps well in the fridge in a ziplock bag for several weeks.