In a double boiler over simmering water, whisk together 3 egg yolks, 1 cup of white granulated sugar, ½ cup of fresh lemon juice, and ¾ teaspoon of salt. Continuously stir for about 10-12 minutes, until thickened.

Preheat your oven to 350°F (175°C). Cream together ¾ cup of softened butter with ¾ cup of brown sugar and ⅓ cup of white granulated sugar until fluffy. Mix in one egg and ½ teaspoon of lemon extract, then gradually incorporate 2 cups of flour and ¾ teaspoon of salt, forming a soft dough.

Portion the dough into balls and place them on a baking sheet with parchment, leaving space between. Create an indentation in each ball. Bake for 14-16 minutes or until edges are lightly golden.

Once cooled, spoon lemon curd into the indents of the cookies, being generous to ensure fullness.

In a double boiler, combine 2 egg whites, ½ cup of sugar, 1 teaspoon of cream of tartar, and a pinch of salt. Whisk until the mixture reaches 165°F. Beat until stiff peaks form, then add 1 teaspoon of vanilla extract.

Pipe fluffy meringue on top of each filled cookie. Use a kitchen torch to lightly brown the meringue.