Preheat the oven to 180 C / Gas 4. Line a baking tray with parchment.
In a large bowl, combine the flour, bicarb, cinnamon and salt. Stir well. Make a well in the centre, then add 100g grape molasses and tahini. Stir till combined. Roll the dough into small balls, 1.5 to 2cm in diameter.
In a bowl or shallow dish, combine an extra tablespoon of grape molasses with about 4 tablespoons of water. In a second dish, add about 4 to 6 tablespoons of sesame seeds. Roll the balls first in the liquid, then in the sesame seeds, and place 5cm apart on the baking tray. Flatten to about 5mm thick with the bottom of a glass.
Bake in the preheated oven for 8 to 10 minutes. Remove and let cool on tray.
You can use plain flour instead of spelt flour. You can also use honey instead of grape molasses, but the flavour will change slightly and the biscuits will not be strictly vegan.