1
Cream the butter and sugar at medium speed until fluffy, about 3 minutes.
2
Mix in the eggs one at a time, then mix in the vanilla and sour cream.
3
Add in the dry ingredients and beat until just combined.
4
Chill the dough for a few hours, or overnight.
5
Preheat oven to 425F.
6
Cover a couple baking sheets with nonstick aluminum foil.
7
Divide the dough into 60 balls, 1 oz each, and distribute these on the baking sheets.
8
Bake for 5 minutes.
9
Using a pancake flipper, smack the balls of dough flat, to about .25" thick. Continue baking for 11-12 minutes.
10
Remove cookies from the oven and baking sheets. Let cool.
11
While the cookies are cooling, mix together the frosting ingredients.
12
After the cookies have completely cooled, refrigerate them for about 30 minutes.
13
Spread the frosting over the cookies, then sprinkle with colored sugar.
14
Let cookies set overnight to develop flavor.