For the cookies: Cream butter and sugar until fluffy. Add pumpkin, egg and vanilla and mix well. Combine flour, baking powder, baking soda, salt, cinnamon and nutmeg. Stir into butter mixture until well blended.
Drop by tablespoonful onto parchment covered baking sheet, about 2 inches apart.
Bake 12-15 minutes, or until golden. Cool.
For the frosting: Cream confectioners' sugar and butter. Add remaining ingredients and beat until smooth.
Ice cookies, then garnish with additional orange zest.
Notes
Recipe adapted from The Food Network.
Recipe by sweet caroline's cooking at https://sweetcarolinescooking.com/2011/10/10/sugar-spice-pumpkin-cookies-w-orange-buttercream-frosting/