In a medium mixing bowl whisk together flour, baking soda, and salt. Set aside.

In a medium mixing bowl using a hand mixer, cream together the butter and sugar until light. Add the eggs one at a time and mix until fully incorporated. Mix in melted chocolate and vanilla. Mix in the flour mixture a quarter cup at a time until well blended. Wrap dough in plastic wrap and refrigerate overnight or several hours. (NOTE: At this point the dough can be frozen for future use.)

Preheat oven to 350 degrees F. Roll out dough on a lightly floured surface to 1/4-inch thickness. Cut out with football-shaped cookie cutter working from the outside to the center. (This makes for less work). Place 1 inch apart on a parchment-lined baking sheet and bake for 10 to 12 minutes. Allow to cool completely before decorating.

In a large mixing bowl using a hand mixer, beat the egg whites with the lemon juice. Add the sifted confectioners' sugar and beat on low speed until combined, smooth, and glossy white. The icing needs to be used immediately or transferred to an airtight container. Using a fine-tipped pastry bag filled with the icing, pipe on the lines replicating the lacing on a football. (NOTE: Water can be added to thin icing if desired.)