In a large bowl, add sugar and lemon zest. Use your fingers to rub the zest into the sugar (this increases the citrus flavor).
Add butter and use an electric mixer to beat mixture until light and fluffy, about 3 minutes.
Add the egg, almond extract and salt. Mix until combined, scraping down the sides of the bowl if necessary. Add the flour and mix just until combined.
Scoop a tablespoon of dough and use your hands to roll it into a ball. Roll dough ball in granulated sugar and place on parchment-lined baking sheet. Using your thumb or the back of a ½ teaspoon measure, create an indentation in the center of the dough ball.
Preheat oven to 350 F. While the oven preheats, place the cookie sheet in the refrigerator for 10 to 15 minutes. This will prevent the cookies from spreading.
Bake cookies for 10 to 12 minutes or until the edges are set. Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.
While the cookies are still warm, fill each indentation with about ½ teaspoon lemon curd. If the cookies puffed up at all, use the back of a clean teaspoon to press the cookies again. Cool completely before serving.
Notes
Store-bought lemon curd may be substituted for homemade. I prefer the Trader Joe's brand.Store cookies in an airtight container in the refrigerator for up to 5 days.