Sweet, salty and crumbly—what more could you ask for!
1 ¾ cups all-purpose flour
1 stick (4 ounces) margarine, at room temperature + 2 tablespoons (for chocolate filling)
¼ cup granulated sugar
finely grated zest from 1 small lemon
1 teaspoon pure vanilla extract
4 oz bittersweet chocolate, broken into small pieces
2 teaspoons light corn syrup
sea salt, to taste
Preheat oven to 350 degrees F. Line a large baking sheet with parchment paper.
In a small bowl, combine lemon zest with sugar. With the tips of your fingers, rub the zest and sugar together until they’re well integrated.
Combine the butter and sugar-zest mixture in the bowl of a stand mixer. Beat them together on medium speed until light and fluffy, about 3 minutes, stopping once or twice to scrape down the sides of your bowl. Add the vanilla extract and beat for a few more seconds. Reduce the mixer speed to low, then add the flour a little at a time. Beat just until just incorporated into the dough -- don’t overmix.
Scoop teaspoon-sized balls of dough and roll them to form small balls. Place the balls about 2” apart on the parchment-lined baking sheets. Using your thumb, make an indentation in the center of each cookie.
Bake about 15 minutes, or until the cookies are only slightly colored around the edges.
When done, remove the baking sheets from oven and transfer the cookies to cooling racks.
Using a double boiler or a small heat-proof bowl set over a pot of simmering water, combine chocolate, 2 tablespoons margarine and corn syrup. Stir until melted and smooth. Cool slightly. When cookies are cool, fill the thumbprints with the chocolate, and then sprinkle with sea salt. Allow about an hour for the chocolate centers to set.