In a medium bowl, combine 2 cups of all-purpose flour and ½ teaspoon of salt, whisking them together to ensure an even distribution.

In a large mixing bowl, beat together ¾ cup of unsalted butter and ¾ cup of granulated sugar on high speed for 3-4 minutes until light and fluffy.

Add 2 egg yolks and 1 teaspoon of vanilla extract to the butter-sugar mixture and mix on medium speed for about 1 minute until fully combined.

Gradually add the flour mixture to the creamed butter mixture, stirring gently until just combined.

Form the cookie dough into a ball, wrap in plastic wrap, and refrigerate for at least 1 hour.

Preheat your oven to 350°F (180°C). Divide the chilled dough into 36 equal portions, rolling each into a ball, and place on a baking sheet.

Using your thumb, gently press down in the center of each cookie ball to create an indentation.

Bake the cookies in your preheated oven for 12-14 minutes, or until the edges turn lightly golden.

While the cookies are still warm, fill each indentation with lemon curd.

Allow the cookies to cool completely on a wire rack before serving.