Mix the flour, cocoa powder, baking soda and salt together in a bowl and set aside.
In the bowl of an electric mixer on medium speed beat the butter and
sugar together until light and fluffy, roughly 2 minutes. Beat in the
eggs and vanilla until combined, then reduce the mixer speed to low and
slowly add in the flour mixture. Beat until just combined.
Form the dough into a disk and wrap with plastic wrap. Refrigerate for about an hour until firm.
Preheat the oven to 350°. Shape the dough into 1¼ inch balls and roll
each ball in the sanding sugar. Place on a cookie sheet lined with
parchment paper. Bake for 10-12 minutes, or until the cookies are set.
They will still look a bit gooey when removed from the oven. Cool on a
wire rack for 5 minutes then remove from the cookie sheet and cool
Whip together butter and cream cheese. Add sugar, vanilla, and only 1 TBS of cold milk at a time until you reach the spreading consistency you desire.
As you can see from the photo above I left some unfrosted, frosted some, and some with the frosting I added about a ½ tsp of crushed up candy cane. They all got gobbled up at a Christmas party we went to. Enjoy!