Lemon Meringue Cookies

Preparation

1. Step 1

   Make the meringue: Heat oven to 250 degrees and line a baking sheet with parchment paper. In a small bowl, stir together both sugars.

2. Step 2

   Working with an electric mixer, beat the egg white, vinegar and salt on medium-high speed until the mixture forms soft peaks, about 3 minutes. Add the sugar mixture 1 tablespoon at a time, beating after each addition. Once the sugar is incorporated, beat 2 minutes more; you’ll have stiff, glossy, white peaks. Put the meringue on the baking sheet and spread it ¼-inch thick. (It will cover only a small part of the sheet.)

3. Step 3

   Bake the meringue undisturbed for 35 minutes. Turn off the heat, prop open the oven door and let it dry for 1 hour. When you’re ready to use it, chop it into pieces about the size of chocolate chips. Precision doesn’t matter.

4. Step 4

   Make the shortbread: Working with a mixer (use the paddle if it’s a stand mixer), beat the butter, both sugars and the salt on medium speed for about 3 minutes, until smooth but not fluffy. On low speed, beat in the yolks, one at a time, followed by the vanilla. Add the flour in three additions, mixing on low until the dough comes together in large clumps. Turn out the dough and knead it into a ball. Cut the ball in half.

5. Step 5

   Shape each half into a 6-inch log. Wrap it and refrigerate for at least 1 hour. (You could also freeze it for up to 2 months; leave it on the counter for 1 hour before baking.)

6. Step 6

   When you’re ready to bake the cookies, heat oven to 350 degrees. Coat 1 or 2 muffin tins with butter (or nonstick baking spray).

7. Step 7

   Slice each log into 12 rounds (each ½-inch thick); drop one into each muffin cup. (If you don’t have enough tins, you can work in batches.)

8. Step 8

   Bake for 21 to 23 minutes, or until the cookies are golden brown around the rims. Transfer the tin(s) to a rack, cool for 5 minutes, then lift the cookies out and onto racks; cool to room temperature.

9. Step 9

   Just before serving, top each cookie with lemon curd, then top with ample chunks of meringue, pressing them into the curd. The meringue will keep in a cool, dry place for a few days, and the cookies can be kept at room temperature for about 3 days. But once you top the cookies, they’re best eaten soon after.