Instructions

• Whisk the flour, cornstarch, baking soda, and salt together in a medium bowl. Set aside.
• In a large bowl using a hand mixer or a stand mixer fitted with a paddle attachment, beat the butter and granulated sugar together on medium-high speed until creamed, about 3 minutes. Add the egg, lemon juice, lemon zest, and vanilla extract and beat on high speed until combined, about 1 minute.
• Scrape down the sides and up the bottom of the bowl. Add the flour mixture and beat on low speed until combined. Dough is thick, creamy, and sticky.
• Cover dough tightly and chill in the refrigerator for at least 3 hours and up to 3 days.
• Remove cookie dough from the refrigerator. If the cookie dough chilled longer than 3 hours, let it sit at room temperature for about 10 minutes.
• Preheat oven to 350°F (177°C). Line baking sheets with parchment paper or silicone baking mats. Set aside.
• Scoop and roll balls of dough, about 1 Tablespoon of dough each, into balls. Roll them in granulated sugar first and then in confectioners’ sugar. Place 3 inches apart on the baking sheets.
• Bake the cookies for 12–13 minutes or until the edges appear set and the centers still look soft.
• Cool cookies for 5 minutes on the baking sheet, and then transfer to a cooling rack to cool completely.
• Cookies stay fresh covered at room temperature for up to 1 week.