Add all the dry ingredients of the crumble layer to a mixing bowl and mix using a fork. Then add the maple syrup, vanilla and the coconut oil. Using your hands mix the oil into the flour mixture until you get a crumbly dough. Keep aside.
Mix all the filling ingredients in a mixing bowl gently using a spoon. Keep aside.
To the prepared pan, add half of the crumble mixture so as to form a layer on the bottom.
Next pour the filling mixture over it. Finally add the rest of the crumble mixture on top to form a sandwich pie.
Place the loaf pan in the oven and bake at 350 F for 45-55 minutes or until the top crumble layer looks golden and toasted.
Remove from the oven and let cool for 10 minutes before cutting into bars.