Ingredients:
- Cookies:
- 9 ounces all-purpose flour (2 cups)
- 1/2 teaspoon salt
- 1/4 teaspoon baking powder
- 3/4 cup butter
- 2/3 cup granulated sugar
- 1 large egg
- 1 1/2 teaspoons vanilla extract
- Icing:
- 1 1/2 cups powdered sugar
- 4 teaspoons egg white powder
- 1/8 teaspoon salt
- 2 tablespoons water
- Additional ingredient:
- Sparkling sugar (optional)