8 tablespoons (1 stick) unsalted butter, softened
1 cup sugar
1 large egg
¼ cup milk
Grated zest and juice of 1 lemon
½ teaspoon pure vanilla extract
2½ cups all-purpose flour
½ teaspoon baking powder
½ teaspoon sail
1 recipe Royal Icing (recipe follows)
For the royal icing
1 large egg white
1 tablespoon fresh lemon juice
2 to 3 cups confectioners’ sugar (use 2 cups for thin Royal Icing to spread on the cookies; use 3 cups for thick Royal Icing to pipe on decorations)
For the cookies
1. Cream the butter and sugar together in a bowl with an electric mixer until light and fluffy.
2. Add the egg to the butter mixture and beat until well combined. Add the milk, lemon zest, lemon juice, and vanilla and mix well.
3. Sift together the flour, baking powder, and salt in a separate bowl and stir to mix.
4. Add the flour mixture to the butter-sugar mixture and beat until well combined, but do not overmix.
5. With floured hands, remove the dough from the bowl and form into a flat round. Wrap with plastic and refrigerate for at least 1 hour or up to 5 days.
6. Preheat the oven to 350 degrees.
7. Lightly grease 2 baking sheets and set aside.
8. Remove the dough from the refrigerator. Let stand at room temperature 15 to 20 minutes if it is too hard to roll out.
9. On a lightly floured surface, roll into a round about ¼ inch thick. Cut with cookie cutters; place the cookies on the prepared baking sheets about 3 inches apart.
10. Bake 12 to 15 minutes, until the cookies are lightly golden around the edges only. Cool 5 to 10 minutes on the baking sheets before removing the cookies to a baking rack to cool completely.
11. To decorate, brush with a layer of thin Royal Icing and sprinkle with colored sugar or use a pastry bag and pipe on thick Royal Icing for added designs.
For the royal icing
1. Combine the egg white and lemon juice in a bowl and beat with an electric mixer until frothy.
2. Slowly add the sugar, about ½ cup at a time, until well blended, light, and fluffy.
3. Add several drops of food coloring, if color is desired, and beat until well blended. Use immediately or refrigerate in an airtight container up to 2 days.