01 - Preheat oven to 350°F and lightly grease a 12-cup mini muffin tin or tartlet pan with coconut oil.
02 - Combine flour, sugar, and salt in a medium bowl. Whisk to incorporate evenly.
03 - Add solid coconut oil to the flour mixture. Use a pastry cutter or fork to blend until mixture resembles coarse crumbs with pea-sized pieces.
04 - Add cold water 1 tablespoon at a time, mixing gently after each addition, until dough just comes together. Do not overwork.
05 - Divide dough into 12 equal portions. Press each portion into muffin cups, pressing dough up the sides to form shells.
06 - Prick bottoms with a fork. Bake for 10-12 minutes until edges are lightly golden. Cool in pan for 5 minutes.
07 - Whisk lemon juice, zest, coconut milk, sugar, cornstarch, turmeric, salt, and vanilla in a saucepan until cornstarch dissolves completely.
08 - Cook over medium heat, whisking constantly, for 4-6 minutes until mixture thickens and begins to bubble. Remove from heat immediately.
09 - Distribute filling evenly among cooled tart shells. Refrigerate for at least 1 hour until completely set and firm.
10 - Top with additional lemon zest or fresh berries if desired. Serve chilled.