Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper.
Whisk together the flour, baking powder, baking soda, and salt in a medium bowl.
2¾ cups (344 g) all-purpose flour, 1 tsp (4 g) baking powder, ½ tsp (2 g) baking soda, ½ tsp (3 g) table salt
Beat the butter and 1¼ cups (250 g) granulated sugar in a large bowl until light and fluffy, about 2 to 3 minutes.
1 cup (227 g) unsalted butter, 1¼ cups (250 g) granulated sugar
Mix in the egg, egg yolk, lemon zest, lemon juice, vanilla extract, and lemon extract, if using, until fully combined.
1 large egg, 1 large egg yolk, 1 tbsp (6 g) lemon zest, 2 tbsps (30 ml0 fresh lemon juice, 1 tsp (5 ml) vanilla extract, ½ tsp (2.5 ml) lemon extract
Add the dry ingredients and mix just until a soft dough forms.
Scoop the dough into 1½ tablespoon portions and roll each one in the remaining ¼ cup (50 g) granulated sugar.
¼ cup (50 g) granulated sugar
Arrange the dough balls about 2 inches (5 cm) apart on the prepared baking sheets.
Bake for 9 to 11 minutes, or until the edges are lightly set and the centers still look soft.
Let the cookies cool on the baking sheet for 5 to 10 minutes before transferring them to a cooling rack to cool completely. If your cookies spread, use the opening of a glass to swirl them into a circle before they cool. This will make them perfectly round.
Whisk together the confectioners' sugar, lemon juice, lemon zest, and melted butter until smooth.
1½ cups (180 g) confectioners' sugar, 2-3 tbsps (30-45 ml) fresh lemon juice, 1 tsp (2 g) lemon zest, 1 tbsps (14 g) unsalted butter
Dip the tops of the cooled cookies into the glaze, allowing any excess to drip off.
Let the glaze set for about 20 minutes, or until the surface is no longer wet.