In a large mixing bowl, combine the flour and salt and set aside.
In the bowl of a heavy duty mixer, beat the shortening at low speed until fluffy. Add the sugar and corn syrup and beat until well blended, then add the egg and the vanilla, beating continuously on low. Slowly add the flour mixture, about 2 tablespoons at a time. (If you are not using a heavy-duty mixer, the dough may become too stiff for the mixer to handle. If so, you may have to add the last of the flour by hand, kneading the dough until all of the flour is fully incorporated.)
Put the dough in a large plastic bag and refrigerate for 2 hours.
To make decorated cutout cookies, preheat the oven to 350 degrees F. Roll out the chilled dough to about 1/8-inch thick on a lightly floured surface. Cut out the dough using tree, snowflake, star, and bird patterns. Place the cookies on greased cookie sheets and bake until golden brown, about 10 to 12 minutes. Cool the cookies on racks before decorating.
To decorate, tint a recipe of royal icing to your desired colors. Keep the icing covered with a damp towel while you are working to prevent it from drying out. To cover a cookie with icing, thin some of the icing with a little water and spread it on the cookie with a knife or metal spatula. Leave some of the icing thick for piping borders or other designs, using the #2 tip. Add dragees, edible glitter, colored sprinkles, or other decorations to the wet icing. To attach candies to un-iced cookies, brush a thin layer of clear piping gel on the cookie with a small paintbrush and add decorations.
Royal IcingRoyal icing is very versatile. It is pure white and dries very hard, so it is perfect for making flowers and bows and delicate piped work. It can be kept in an airtight container at room temperature for 2 weeks. You should stir the icing to restore its original consistency after storage, but do not rebeat. Royal icing does not work well in high humidity.
5 tablespoons meringue powder (found in cake decorating stores)
1/2 cup minus 2 tablespoons water
2 egg whites*, at room temperature
1/2 teaspoon cream of tartar
2 teaspoons water
1 pound confectioners' sugar
Place all of the ingredients in the bowl of an electric mixer and beat slowly until they are all blended. Then beat at medium speed until the icing forms stiff peaks, about 5 minutes. Add more sugar if the icing is not stiff enough, or a few drops of water if it is too stiff. Use immediately or cover the bowl with a damp cloth to prevent drying when not in use. Allow at least 24 hours for royal icing decorations to dry, at room temperature.
Yield: 2 1/2 cups