Preheat oven to 350. Grease a 12X 18 or 10 X 15 inch jelly roll pan. Combine flour and sugar for crust in food processor fitted with metal blade. Cut the butter into one tablespoon pieces. Add to dry ingredients in food processor. Process about 15 seconds until well blended. Pour into jelly roll pan and press crumbs into pan to make a crust. Bake for 12-18 minutes or until crust just begins to brown.

Prepare icing by placing confectioners sugar in food processor fitted with metal blade. Combine milk, melted butter, lemon juice and almond extract. With the food processor running, pour liquid ingredients into processor bowl. Stop machine, scrape sides and bottom of bowl and process again briefly. Put icing in small bowl and set aside.

Without cleaning food processor bowl, place the walnuts in processor fitted with metal blade. Process to a medium sized chop. Add remaining ingredients and process to blend well. Spread walnut mixture over baked shortbread crust. Bake 17-20 minutes (the top will be quite brown.) Allow cookies to cool 15-20 minutes. Pour on icing and spread thin. If icing forms crust on top before it is used just stir crust into icing and use. Allow cookies to cool before cutting.