Preheat the oven to 375°F (190°C). Line a baking sheet or pizza pan with parchment paper.
Prepare the filling by combining the sliced pears, sugar, lemon juice, vanilla extract, and flour in a medium bowl. Toss until evenly coated and set aside.
In a separate bowl, whisk together the flour, sugar, and salt for the crust.
Add the melted coconut oil or vegan butter and cold water. Stir until a dough forms and comes together easily.
Transfer the dough directly onto the prepared parchment-lined baking sheet. Using your hands, gently press and shape the dough into a circle about 10 to 12 inches in diameter.
Arrange the pear filling in the center of the dough, leaving about a 2-inch border around the edges.
Fold the edges of the dough over the filling, pleating as needed to create a rustic tart shape.
Brush the crust with coconut milk, maple syrup, or agave.
Sprinkle the crust with turbinado sugar.
Bake for 35–40 minutes, or until the crust is golden brown and the pear filling is bubbling.
Allow the tart to cool slightly before slicing and serving. Enjoy warm or at room temperature.