Preparation Steps

• Whisk together the flour, cornstarch, and salt in a medium bowl; set aside.
• In a stand mixer fitted with the paddle (or with a hand mixer), beat the butter and granulated sugar on medium speed until smooth and creamy, about 2 minutes. Mix in the lemon extract and vanilla until combined.
• Add the lemon zest and mix just 10–15 seconds to distribute the oils without overworking the butter.
• Add the dry ingredients all at once. Mix on low, pulsing if needed to avoid a flour cloud, until the dough looks sandy and starts to clump. Stop as soon as it holds together when pinched—do not overmix.
• Divide dough in half. Press each portion into a 1-inch-thick disk, wrap tightly, and chill until firm enough to roll, 45–60 minutes.
• Preheat the oven to 350°F (177°C). Line 2 baking sheets with parchment paper.
• Working with one disk at a time, roll the dough between two sheets of parchment to 3/8-inch thickness. Cut 2-inch rounds, gathering and rerolling scraps once if needed. Arrange on prepared sheets about 1 inch apart, then chill the cutouts for 10 minutes for the cleanest edges.
• Lightly brush the tops with water and sprinkle generously with turbinado sugar.
• Bake 12–15 minutes, rotating pans halfway, until the rims are just turning pale golden and centers look set. Cool on the sheet for 5 minutes, then transfer to a rack to cool completely.