PreparationMake cookies: Sift together flour, cinnamon, and salt. Pulse walnuts with 2 tablespoons sugar in a food processor until finely ground (be careful not to grind to a paste). Beat together butter and remaining sugar with an electric mixer until pale and fluffy. Beat in eggs until combined. Mix in flour mixture and nuts at low speed just until blended. Form dough into a disk and chill, wrapped in plastic wrap, until firm, about 1 hour. Preheat oven to 325°F. Keeping remaining dough chilled, roll out half of dough 1/4 inch thick on a lightly floured surface. Cut out cookies with a 2 1/2- to 3-inch floured cookie cutter. Chill scraps. Arrange cookies 1 inch apart on greased baking sheets. Bake cookies in batches in middle of oven until firm but not browned, about 10 minutes. Transfer cookies to a rack to cool. Make cookies with remaining dough in same manner, rerolling scraps no more than twice. Ice and decorate cookies: Whisk together powdered egg whites and water, then stir in confectioners sugar and lemon juice until smooth and spreadable. Spread a thin layer of icing on 1 cookie with a metal spatula or knife and sprinkle lightly with walnuts. (Use your imagination and decorate more elaborately if you like.) Decorate remaining cookies in same manner. Let icing harden, about 1 hour, before storing cookies.
PreparationMake cookies: Sift together flour, cinnamon, and salt. Pulse walnuts with 2 tablespoons sugar in a food processor until finely ground (be careful not to grind to a paste). Beat together butter and remaining sugar with an electric mixer until pale and fluffy. Beat in eggs until combined. Mix in flour mixture and nuts at low speed just until blended. Form dough into a disk and chill, wrapped in plastic wrap, until firm, about 1 hour. Preheat oven to 325°F. Keeping remaining dough chilled, roll out half of dough 1/4 inch thick on a lightly floured surface. Cut out cookies with a 2 1/2- to 3-inch floured cookie cutter. Chill scraps. Arrange cookies 1 inch apart on greased baking sheets. Bake cookies in batches in middle of oven until firm but not browned, about 10 minutes. Transfer cookies to a rack to cool. Make cookies with remaining dough in same manner, rerolling scraps no more than twice. Ice and decorate cookies: Whisk together powdered egg whites and water, then stir in confectioners sugar and lemon juice until smooth and spreadable. Spread a thin layer of icing on 1 cookie with a metal spatula or knife and sprinkle lightly with walnuts. (Use your imagination and decorate more elaborately if you like.) Decorate remaining cookies in same manner. Let icing harden, about 1 hour, before storing cookies.