Why It Works
- Powdered sugar and tapioca starch reduce the need for flour, weakening the dough for a deliciously delicate cookie.
- Tapioca breaks down at relatively low temperatures, so the cookies taste buttery and rich, not starchy.
- Preparing the dough in a food processor helps release essential oil from the lemon zest, boosting the flavor of the dough.
If you've never had a lemon meltaway, brace yourself for the most incredibly delicate cookie, like a cross between lemon shortbread and cotton candy. Its unique texture comes from tapioca starch, which loses its starchy flavor in the oven (unlike cornstarch, which tastes chalky and dry). Pick up a bag in the baking aisle, or from your favorite Asian market. You'll be rewarded with a light and lemony shortbread that truly melts away with every bite.
- For the Dough:
- 3 ounces low-protein all-purpose flour (2/3 cup; 85g), such as Gold Medal
- 1 1/8 ounces tapioca starch (1/4 cup; 30g)
- 1 ounce powdered sugar (shy 1/4 cup; 30g), preferably tapioca-based (most organic brands are tapioca-based)
- 1/8 ounce grated zest from 1 lemon (1 tablespoon; 4g)
- Pinch of kosher salt
- 4 ounces cold unsalted butter (1 stick; 115g), cut into 1/4-inch dice
- 1/4 teaspoon lemon oil or extract, optional
- To Finish:
- 2 ounces powdered sugar (1/2 cup; 55g)
To Make the Dough: In the bowl of a food processor, combine flour, tapioca starch, powdered sugar, lemon zest, and salt. Cover with a sheet of plastic wrap to contain the fine dust, close lid, and process until zest disappears. Add butter and lemon oil, if using, and pulse to form a smooth dough. With flour-dusted hands, roll dough into a 10-inch log about 1 inch thick. Wrap tightly in plastic and refrigerate until cold, about 4 hours or up to 1 week.
Baking the Cookies: Adjust oven rack to middle position and preheat to 350°F. Slice chilled dough into 1/4-inch rounds and arrange on parchment-lined half sheet pan, leaving about an inch between each cookie. Bake until firm and just barely golden around the edges, about 12 minutes.
To Finish: When they are cool enough to handle, but still slightly warm, gently flip the cookies upside down. Sift about 1 ounce of powdered sugar on top, then flip right side up and sift another 1 ounce on top. Once cool, enjoy with hot tea or as a garnish for ice cream and sorbet. Store leftovers at room temperature in an airtight container for up to 2 weeks.
This dough will not tolerate any more than a few drops of liquid, so take care when experimenting with extracts, juice, or liquors.