In a mixing bowl, combine all-purpose flour, powdered sugar, and salt. Cut in chilled butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs. Gently knead the dough just until it holds together, then roll it out on a floured surface. Cut out circles for mini tart pans, prick the bases with a fork, and chill in the refrigerator for 30 minutes.

Preheat your oven to 350°F (175°C). Once chilled, remove the tart crusts from the fridge and line them with parchment paper. Fill with pie weights or dried beans. Bake for 15-18 minutes, or until the edges turn lightly golden. Carefully remove the weights and parchment, then bake for an additional 5 minutes until the crust is fully set. Let the crusts cool completely.

In a saucepan over medium heat, whisk together fresh lemon juice, granulated sugar, eggs, lemon zest, and vanilla extract. Cook the mixture, stirring continuously, until it thickens and coats the back of a spoon—this should take about 8-10 minutes. Remove from heat, allowing it to cool slightly before pouring it into the cooled tart shells.

Using a clean mixing bowl, beat room temperature egg whites with a hand mixer on medium speed until soft peaks form. Gradually add granulated sugar, one tablespoon at a time, while continuing to beat for about 5 minutes until stiff peaks form and the mixture is glossy. If desired, add a few drops of lilac food coloring and gently fold to incorporate.

Transfer the meringue to a piping bag fitted with a star-shaped tip. Start from the edges of each mini tart, piping the meringue in a circular motion, and then fill the center, creating a lovely swirl. Alternatively, use a spatula to spread the meringue, ensuring it covers the lemon curd completely.

Lightly toast the meringue on the mini lemon tarts using a kitchen torch until golden brown, which should take just a minute or two. If you don’t have a torch, place the tarts under the broiler for 1-2 minutes, watching closely to prevent burning. Once done, let the mini lemon tarts with lilac meringue cool before serving.