Double-Chocolate Thumbprint Cookies

Preparation

1. Step 1

   Make the cookies: Whisk together the flour, salt and cinnamon in a small bowl.

2. Step 2

   Place a heatproof medium bowl over a saucepan of gently simmering water; don’t let the water touch the bottom of the bowl. Drop in the chunks of butter and scatter over the chocolate. Heat, stirring now and then, until the butter and chocolate are melted, but not so hot that they separate, 5 to 7 minutes.

3. Step 3

   Remove the bowl from the saucepan and whisk in the sugar. (Don’t be alarmed when the mixture turns grainy.) One by one, add the cold eggs, whisking vigorously until the mixture is thick and smooth, and the whisk leaves tracks. Beat in the vanilla, then switch to a spatula and add the flour in 3 additions, stirring gently between each addition, until the flour disappears into the dough. Press a piece of plastic wrap against the surface of the dough and refrigerate for at least 2 hours or up to 4 days.

4. Step 4

   When you’re ready to bake, center a rack in the oven and heat it to 350 degrees. Line 2 baking sheets with parchment paper or silicone baking mats. Put the sanding or granulated sugar in a small bowl and, if you’ve got one, have a cork from a wine bottle at hand.

5. Step 5

   Using a small cookie scoop or measuring spoon, scoop mounds of dough, each a scant tablespoon. Roll the dough into balls and then roll the balls in the sugar to coat. Place the balls on the baking sheets, giving them 1½ inches or so of space to spread. Press the cork into the center of each cookie or use your thumb to make an indentation.

6. Step 6

   Bake 1 sheet for 10 to 12 minutes, or until the cookies feel firmish. Transfer the baking sheet to a rack. The indentations will have puffed in the oven, so you’ll want to press them down again. Repeat with the second sheet. Let cookies cool completely.

7. Step 7

   Fill the prints: Melt milk, dark or ruby chocolate in a heatproof bowl set over a saucepan of simmering water. If using white chocolate, add oil before melting and stir until smooth. While the chocolate is still warm and fluid, use a small spoon to fill each indentation to the brim, letting the chocolate fall from the end of the spoon. Slide the cookies into the refrigerator for about 10 minutes to set the chocolate. The cookies will keep for about 5 days in a covered container at room temperature.