In a medium bowl, whisk together the flour, cornstarch, and salt until combined. Set aside.

In a large bowl using a mixer, beat the butter and granulated sugar together on medium-high speed until creamed, about 3 minutes.

Add the lemon zest, lemon juice, egg, and vanilla bean paste and beat on high speed until combined, about 1 minute.

Add the dry ingredients to the wet ingredients and mix on low speed until combined. Cover and refrigerate for at least 3 hours.

Line large baking sheets with parchment paper.

Scoop cold dough (about 1 tablespoon of dough each) and roll into balls. Roll each ball in granulated sugar.

Make an indentation in the center of each cookie dough ball and fill with ½ teaspoon of lemon curd.

Preheat oven to 350°F (177°C). Chill cookies in the refrigerator while the oven preheats.

Bake for 12-13 minutes, or until edges appear set and are lightly browned. Cool on the baking sheet for 5 minutes before transferring to a wire rack.

In a small bowl, whisk together confectioners’ sugar and lemon juice. Drizzle over cooled cookies.

Icing will set at room temperature in about 30 minutes.