01 - Preheat oven to 350°F. Lightly grease a 12-cup mini muffin tin or tartlet pan.
02 - In a medium bowl, combine flour, sugar, and salt. Add solid coconut oil and blend with a pastry cutter or fork until mixture resembles coarse crumbs. Add cold water 1 tablespoon at a time, mixing until dough forms.
03 - Divide dough into 12 equal portions. Press each portion into the bottom and up the sides of each muffin cup to form mini tart shells.
04 - Prick the bottoms of tart shells with a fork. Bake for 10-12 minutes until lightly golden. Remove from oven and let cool completely.
05 - In a saucepan, whisk together lemon juice, lemon zest, coconut milk, sugar, cornstarch, turmeric, salt, and vanilla extract until smooth.
06 - Place saucepan over medium heat, whisking constantly, until mixture thickens and just begins to bubble, about 4-6 minutes. Remove from heat immediately.
07 - Pour warm lemon filling evenly into cooled tart shells. Smooth tops with a spoon or small offset spatula.
08 - Refrigerate tarts for at least 1 hour or until filling is completely set and firm.
09 - Garnish with additional lemon zest or fresh berries if desired. Serve chilled.