Oh, this is very important: If you manage to find the sanding sugar, you MUST LINE THE COOKIE SHEET WITH A SILICONE BAKING SHEET, PARCHMENT PAPER, OR WAX PAPER IF THAT’S ALL YOU HAVE. Only skip this step if you want broken cookies. When the sugar melts in the oven, it bonds itself to the cookie sheet that would require a super power to get it free. Trust me, I have tested it too many times without the paper.
lemon butter biscuits with lemon thyme glaze
2 sticks (224g) unsalted butter, at room temperature
2/3 cup granulated sugar
zest of 1 lemon (the zest of 2, if you have an extra one lying around)
1 egg, separated
1 teaspoon salt
2 1/2 cups unbleached all-purpose flour
1 tablespoon freshly squeezed lemon juice
1/4 cup sanding sugar*
1. In the bowl of an electric mixer fitted with the paddle attachment, cream together butter, sugar, lemon zest, and salt. Mix until light and fluffy. Add in egg yolk, and mix until well combined, scraping down the sides of the bowl as necessary. Mix in flour and lemon juice until just incorporated. Turn the mixture onto a floured board, and knead gently to ensure all ingredients are well distributed.

2. Shape the dough into 2 cylinders, each about 2 inches in diameter and 15 inches long. Beat the egg white in a small bowl, and brush on all sides of the cylinders. Roll in sanding sugar, then roll up in parchment paper and refrigerate for at least 30 minutes. (You can freeze them at this time if you wish.)

3. Preheat oven to 350 degrees (180 degrees celsius). LINE COOKIE SHEETS WITH PARCHMENT PAPER OR A SILPAT. Cut cylinders into 1/4 inch slices. Lay flat on cookie sheets at least an inch and a half apart. Bake for 18-20 minutes in the top third of the oven until edges begin to turn a light golden brown. Let cool in the pan for at least 5 minutes, then transfer to a cooling rack. Let cool completely and drizzle with glaze.
for the glaze:
1 cup (100g) confectioner’s (icing) sugar
2-3 tablespoons freshly squeezed lemon juice
1/2 teaspoon pure vanilla extract
1 tablespoon lemon zest
1 teaspoon fresh thyme, finely chopped
1. Mix all ingredients in a small bowl, adding a small amount of the lemon juice at first, and then adding more, to create the desired consistency.

*Sanding sugar is large granulated sugar available in cake decorating supply stores. Mine was the Wilton brand, called “Sprinkles.” I found it at JoAnn.)
** Don't these look good ? I got the recipe from -
