Family Tested & Approved
Beat butter until creamy. Add half of the flour with sugar, egg yolks, and vanilla. Beat until thoroughly combined. Beat in remaining flour.
Cover and chill for 1 hour or until easy to handle.
Shape into 1 inch balls (slightly overfill small cookie scoop.) Roll in egg whites, then in walnuts. Place 1 inch apart on greased cookie sheets. Press center down with your thumb.
Bake at 375 degrees for 10-12 minutes or until edges are slightly brown. Cool. Fill centers with frosting. If you like, tint your frosting to match the occasion. Makes 28-30 cookies.