1Preheat oven to 170°C (approximately 350°F.
2With an electric mixer, beat butter until creamy and gradually add sifted powdered sugar, while scraping down sides of bowl.
4Stir in sifted wheat flour and salt. Shape dough into a ball, wrap in plastic wrap and refrigerate for 1 hour.
5Place dough between two sheets of parchment paper and roll out to desired thickness.
6Cut out cookies in desired shapes and place on baking sheet lined with parchment paper.
7Bake at 170°C (approximately 350°F) for about 12 minutes.
8Leave cookies on the baking sheet for 5 minutes before cooling on a wire rack.
9Cool completely before decorating.
10For the icing, with an electric mixer, beat white egg until it starts to foam and then add sifted powdered sugar for a toothpaste-like texture that will outline the cookies.
11To fill in outline, add a few drops of water to icing and brush over cookie to fill.
12Tint icing with food dye in any color, as desired.