Preheat oven to 400F. Lightly grease a 9×13 baking dish.
Add dates to bowl; pour hot water to cover. After 10 minutes, drain.
In a large bowl, add flour. Add dairy-free butter, using a pastry blender or fork, cut butter into small pieces and incorporate into the flour. The mixture should look like coarse, wet sand.
Slowly add water 1 Tablespoon at a time, stirring, until a dough forms. Dump the dough onto a floured surface; knead until a smooth dough forms. Using a rolling pin, roll dough into a rectangle the size of your baking dish. Place dough into the pan and press down to ensure even thickness.
Add drained dates and non-dairy milk to a blender. Blend until smooth.
Warm a medium-sized saucepan over medium-low heat. Add date mixture, brown sugar, maple syrup, and molasses, stirring constantly. Cook for 10 minutes, until the mixture begins to thicken. Add flax meal, cornstarch, vanilla, cinnamon, and salt. Stir and cook for 5-10 more minutes, stirring constantly.
Chop 1 cup of the pecan halves. Add the chopped pecans to the sugar mixture; stir to combine.
Pour the mixture over the crust. Arrange remaining 1/2 cup pecan halves on top of the filling.
Bake for 30-35 minutes. Let sit for 10-15 minutes until the filling has hardened a bit.