In a small bowl, mix jam and chia seeds, set aside. The seeds will expand a little and thicken up the jam while you prepare the crust.
In another medium bowl, add whole-wheat flour, tahini paste, hemp/sesame seeds, syrup, salt and vanilla extract or vanilla powder. The dough must be moist without being too wet. It should stick together easily. If it is too dry, add 1 tablespoon (15 ml) of plant-based milk. Set aside a 1⁄3 cup of the resulting dough.
Sprinkle the dough evenly in the prepared pan. Press it down evenly all over the bottom of the pan. Cover with the jam mixture, spreading it all over with spatula. Crumble the reserved dough on top, pressing slightly on top of the jam.
Bake 25 minutes or until the crumbs on top are golden brown.
Place on a wire rack and cool for at least 30 minutes before slicing and serving.
Store in an airtight container at room temperature for up to 2 days.