Place a fine mesh sieve or a sifter over a medium mixing bowl and add the flour and salt. Sift the dry ingredients into the bowl and set aside.

In a mixing bowl, combine the butter and sugar; using a hand held mixer on medium-high speed cream the butter and sugar together until the mixture is light in color and has a fluffy texture. Scrape down the sides of the bowl with a rubber spatula and then add the vanilla extract, lemon zest and egg. Beat until blended, 1 or 2 minutes longer. On low speed, gradually add the sifted flour and salt, mixing until just blended.

Remove the dough from the bowl and divide into 2 balls. Place each half between 2 pieces of waxed or parchment paper and roll into 5-inch diameter disks. Place the dough on baking sheets and refrigerate until firm, at least 2 hours or as long as 24 hours.

When you are ready to roll and bake the cookies, preheat the oven to 350 degrees F. Line a baking sheet with silicone liners or parchment paper. Place 1 disk of the cookie dough on the work surface and remove the top sheet of paper. Lightly dust the surface of the dough with flour. Roll the dough out starting from the center to an even thickness of 1/8-inch. Using decorative cookie cutters cut the dough directly on the parchment paper. Use a spatula to transfer the dough to the lined baking sheet. Place the cookies at least 1/2-inch apart.

Gather the dough scraps and reroll them to make additional cookies. Only reroll the dough once.

Bake the cookies 1 sheet at a time for 10 to 12 minutes or until cookies are golden around the edges and firm to the touch. Transfer cookies to a wire rack to cool.

The cookies can be stored in resealable plastic containers or cookie tins for 1 week. To frost the cookies prepare a recipe of royal icing as follows and decorate as desired.

Place all of the ingredients in the bowl of an electric mixer and beat slowly until well blended. Then beat at medium-high speed until the icing forms stiff peaks, 6 minutes. If icing is not stiff enough add more sugar if it is too stiff add more milk. Use immediately or place in a plastic container with a lid until ready to use. Allow icing to dry for at least 24 hours before packaging.

Yield: About 2 1/2 cups