Almond Thumbprint Cookies
Preheat oven to 350° F.
Line two small baking sheets (or one large one) with parchment paper.
In a small bowl, whisk together almond meal and flour
In another 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, egg, and lemon zest/sugar mix in the bowl of a stand or hand mixer.
Beat on medium speed until light and fluffy (~ 3 minutes), stopping once or twice to scrape down the sides of your bowl with a rubber spatula.
Add the vanilla extract and beat for a few more seconds.
Reduce the speed of the mixer to low, and add the almond meal-flour mixture a little at a time. Beat just until the dough has just come together, being careful not to over-mix.
Scoop teaspoon-sized balls of dough (a melon scoop works well) 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. (** Make sure you don't press through the dough, but make sure the centers are plenty deep and wide to hold the chocolate filling)
Bake about 15 minutes, or until the cookies are only slightly colored around the edges, be careful to not over-bake. (About 10 minutes in, I often check the thumbprint indentations -- if they seem too shallow, remove the cookie sheet and depress the centers while the dough is still soft. The curved back of a melon scoop or teaspoon works well.)
When done, remove the baking sheets from the oven and transfer the cookies to cooling racks. (One trick to doing this is to keep the cookies on the parchment paper, and slide the parchment onto the cooling rack)
Dark Chocolate Filling
Using a double boiler, or a small heat-proof bowl set over a pot of simmering water, combine chocolate, 2 Tbsp butter, and golden syrup.
Stir until melted and smooth.
Finish the Cookies
When the cookies are cool, fill the thumbprints with the chocolate filling, and then sprinkle them with sea salt.
Allow about an hour for the chocolate centers to set.