Preparation Steps

• Line two baking sheets with parchment paper. In a small bowl, stir the lemon curd until smooth and glossy; if very thick, warm it for 10 seconds in the microwave to loosen. Set aside at room temperature.
• Combine the sugar and lemon zest in a large mixing bowl. Use your fingertips to massage the zest into the sugar until the sugar is fragrant and slightly damp, about 30 seconds.
• Add the softened butter to the citrus sugar and beat with a hand mixer (or stand mixer fitted with the paddle) on medium-high until pale and fluffy, 2–3 minutes.
• In a small bowl, whisk the egg with the almond extract. Beat this into the butter mixture on medium speed just until creamy and fully emulsified, about 30–45 seconds.
• Sift together the flour, cornstarch, and salt. Add to the bowl and mix on low just until the dough comes together and no dry streaks remain. The dough will be soft but not sticky.
• Pat the dough into a 1-inch-thick slab, wrap, and chill until slightly firm, 20–30 minutes. While the dough chills, preheat the oven to 325°F (165°C) with a rack in the center.
• Scoop dough into 1-tablespoon portions (about 25–28 g each), roll into balls, and arrange on the prepared sheets, spacing about 2 inches apart. Press a deep well in the center of each with your thumb or the back of a 1/2-teaspoon measure.
• Bake for 7–8 minutes, until the edges look set but the cookies are still pale. Remove the sheets from the oven and, while hot, gently press the centers again to refresh the wells.
• Spoon about 1 rounded 1/2 teaspoon (up to 1 teaspoon, if your wells are deep) lemon curd into each indentation.
• Return the cookies to the oven and bake another 4–6 minutes, until the bottoms are lightly golden and the curd edges look just set with a slight jiggle in the center.
• Cool on the baking sheets for 10 minutes to firm, then transfer to a wire rack to cool completely. Refrigerate any leftovers in an airtight container.