Mix together butter, 2T powdered sugar and flour. Mixture will be crumbly......use hands to form a ball.
Flatten dough ball and roll out on floured surface, sprinkling flour on top of dough to prevent sticking. *The dough is dry and will crack while rolling out....stop and push together as needed to make a smooth dough circle. Dough should be between ⅛ and ¼ inch thick.
Cut with circle cutter. *I use a 1¼ inch cutter.
Place onto prepared cookie sheet, ungreased.
Bake for 18 minutes. Allow to cool completely.
Make frosting by mixing all ingredients with an electric hand mixer, until smooth and creamy.
Frost cookies by putting a dollop on the bottom of one cookie and topping with the bottom of another cookie.