Using a hand mixer, cream butter and flour. Dough will be very dry.
Mix in powdered sugar, salt, baking powder, vanilla extract and almond extract until well combined. Stir in walnuts last.
Shape small pieces of dough into little crescent shapes using hands (or small balls). Place in rows on ungreased cookie sheets (parchment paper or silpat may be used). Cookies can be spaced fairly close together, they do not spread much.
Bake at 325 degrees for about 25 minutes, or until bottom of cookies are lightly browned. Let cookies cool completely. Toss gently with powdered sugar.