Sift the flour, baking powder and salt together in a bowl and set aside. Cream the butter and sugar together in the bowl of an electric mixer fitted with the paddle attachment. Add the eggs and vanilla and mix on low speed until well combined. Scrape the bowl with a rubber spatula.
Gradually add the dry ingredients to the butter mixture, occasionally scraping the bowl. Wrap the dough in plastic wrap and chill the dough in the refrigerator until firm.
Preheat the oven to 350 degrees.
Roll the dough out on a floured surface 1/8th-inch-thick and cut into shapes with animal cookie cutters. Place the cookies on a sheet pan covered with parchment paper, and bake for 8 to 12 minutes, depending on the size. Cookies should be golden brown on the edges. After cookies have cooled and are firm, they are ready to decorate, if desired.
For the decoration, fill a pastry bag fitted with a small plain tip with Royal Icing. Place each cookie on a piece of parchment paper and outline it with a thin line of Royal Icing around the entire edge of the cookie. Allow the icing to set.
Place 1/4 cup of Royal Icing in a small bowl and mix it well with 1/4 teaspoon of the egg whites or water. Continue mixing and adding egg whites or water until the icing is the consistency of maple syrup.
Using a number 12 artist's brush push a few dollops of the thinned icing around the top of each cookie until it is completely covered to the edge. Allow the cookies to sit overnight to harden. Reserve the remaining Royal Icing.
Place Royal Icing in a small bowl and mix in several drops of black food coloring. Continue mixing and adding food coloring until you have the desired color. Spoon the black icing into a pastry bag fitted with a small plain tip and outline each cookie with a thin line of icing and decorate, as desired. For each additional colored icing, repeat the process. Allow the icing to set.
Place the confectioners' sugar in the bowl of an electric mixer fitted with the paddle attachment, add the eggs whites and lemon juice and beat at medium speed until the sugar and eggs are completely mixed and the icing is thick and white.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.