1.  To prepare cookies, preheat oven to 350F. In bowl of mixer, cream butter and sugar until smooth. Beat in extracts and egg. Add baking powder and mix until combined. 

2.  Slowly add flour, one cup at a time, scraping down bowl if needed. Dough may look crumbly – continue to mix until dough comes together. Dough will be very stiff. If it sticks to sides of bowl, add more flour.

3.  Divide into workable batches, roll out to ¼” thickness on floured surface, and cut. Transfer cookies to baking sheet.

4.  Bake 8 minutes. Let cool on sheet until firm enough to transfer to cooling rack. 

5.  To prepare icing, whisk all ingredients except powdered sugar in medium bowl until all powder is incorporated and mixture looks frothy. 

6.  Pour mixture into bowl of stand mixer with paddle attachment. With mixer on low speed, slowly add powdered sugar. Continue to mix 2-3 minutes. Increase speed to medium and mix 1 minute. Increase speed to high and mix 30 seconds, or until mixture resembles marshmallow fluff. Icing should form a soft peak when checked with a spoon. 

Store in airtight container 3-4 days at room temperature or freeze. (Thaw and rewhip before using.)