1. Preheat the oven to 350°F and grease a 24-cup mini muffin tin.

2. In a bowl, combine flour, sugar, and salt, then cut in cold butter until mixture resembles coarse crumbs.

3. Press dough into each muffin cup and prick bases with a fork, then bake for 10-12 minutes until lightly golden and cool.

4. In a saucepan, whisk sugar, cornstarch, water, lemon juice, and zest over medium heat until thickened.

5. Whisk in egg yolks and cook for 3-4 minutes until smooth, then remove from heat and stir in butter.

6. Spoon lemon curd into cooled crusts and smooth the tops.

7. Beat egg whites until foamy, add cream of tartar, then gradually beat in sugar until stiff peaks form, and mix in vanilla.

8. Pipe or spoon meringue over lemon filling, covering edges to seal.

9. Bake at 400°F for 5-6 minutes or use a kitchen torch to toast the meringue until golden.

10. Cool completely before removing from tin and serve.