First, Make The Lemon Curd:

1. Set Up A Double Boiler. Add 2 inches of water to a small saucepan and set out a glass heatproof bowl that fits on top of the saucepan without touching the water. Bring the water in the saucepan to a simmer over medium-high heat.
2. Combine. In the heatproof bowl, combine sugar, lemon zest, lemon juice, and eggs. Whisk to combine well, then set the bowl over the saucepan of simmering water. Whisk, dropping in the cubes of butter. (They’ll look a little clunky or separated at first, but will smooth out as the mixture heats up)
3. Cook lemon curd 20-25 minutes, or until it reaches 170 degrees F and it has thickened enough to coat the back of a spoon. (If you run a finger down the back of the spoon, it should leave a clear trail, and the lemon curd should be thicken enough to stick to the spoon)
4. Strain the lemon curd through a fine mesh strainer into a glass bowl or container.
5. Stir in vanilla extract & cool to room temperature.
6. Cover & Chill. Press plastic wrap or food wrap down onto the surface of the lemon curd (this prevents a film or “skin” from forming) and chill at least 2-3 hours, or until totally chilled. Lemon curd will keep 1 week in the refrigerator or frozen for 2-3 months, so you can make it in advance, if needed.

Then, Make The Cookie Dough:

1. Combine Sugar & Lemon Zest in a large mixing bowl or the bowl of a stand mixer. Rub the sugar and zest together with your fingers for 30-60 seconds, until the sugar is fragrant with the aroma of lemon and the sugar is evenly coated in zest.
2. Add Melted Butter and mix to combine.
3. Mix In Eggs, one at a time, until the dough is smooth.
4. Add Lemon Juice, Vanilla & Almond Extract and mix to combine.
5. Add Dry ingredients. Mix in the gluten-free flour, baking powder, and salt and stir just until the dough is combined. At this point, the dough will be soft, more like a thick brownie batter than a scoop-able dough. This is normal!
6. Chill Cookie Dough 2 Hours to allow it to firm up to a scoop-able texture. (This also prevents the cookies from spreading too much in the oven–don’t skip this step!)

Assemble & Bake The Cookies

1. Preheat & Prep. When your lemon curd and cookie dough are chilled, preheat the oven to 350 degrees F. Set out two sheet pans and line with parchment paper. (This way you can alternate pans with each batch so you don’t put cool dough on a hot baking sheet,) Place the granulated sugar in a shallow bowl and the powdered sugar in separate a shallow bowl.
2. Scoop & Roll. Use a medium cookie scoop to scoop 2-Tablespoon balls of cookie dough. Roll the each ball smooth between your palms, then drop into the granulated sugar. Roll to coat, then roll in powdered sugar to coat completely (you can use your fingertips to press the powdered sugar onto the cookie a bit, if needed). Place 6 cookie dough balls on the first cookie sheet and return the remaining dough to the fridge.
3. Indent. Use the back of a 1/2-Tablespoon measuring spoon to indent the cookies in the center of each dough ball, carefully pressing to only reach about halfway down (you don’t want to press the spoon all the way through the cookie dough ball!)
4. Fill. Measure 1 teaspoon scoops of lemon curd into the well of each cookie dough ball. (It will spread into an even layer as the cookies bake.)
5. Bake & Cool. Bake the cookies 10-12 minutes per batch, until the cookies have spread, the powdered sugar has crackled, and the cookies look just set around the edges. (Mine are done at 10 minutes.) Let the cookies cool 5 minutes on the baking sheet before transferring to a wire rack to finish cooling completely. Repeat this process with the remaining cookie dough, alternating cookie sheets with each batch, until all cookies are baked.
6. Serve & Store. Enjoy right away or store in an airtight container in the fridge 2-3 days. You can also freeze cookies for 2 months. (I prefer these cookies chilled, like lemon bars!) Leftover lemon curd will keep up to 1 week in the fridge or 2 months in the freezer.