Prepare: Preheat your oven to fan-forced 160°C/320°F or conventional 180°C/356°F. Lightly grease the base and sides of a round 9" tart tin with oil or vegan butter and lightly dust with flour.
Mix and chill the dough: Add the flour, vegan butter, molasses, spices, and salt to a food processor. Blitz for a few seconds until the ingredients are mixed and form a loose dough. Press the dough into a ball and flatten it into a disc. Wrap in clingfilm or place in an airtight container and refrigerate for 30 minutes.
Roll out the dough: Roll out the chilled dough so that it is an inch or so larger than the circumference of the tart tin. Carefully lift the pastry over the tin and use your fingers to ease the pastry into the tin gently. Use a knife to cut around the edges, allowing it to rise slightly higher than the sides of the pan. Pierce the dough several times using a fork.
Bake: Take a sheet of parchment paper and cut it into a circle slightly larger than the tart. Rest it on top of the pastry and fill the base with dried beans, rice, lentils, or baking beads. Parbake in the oven for 12 minutes. Then carefully remove the beans/baking beads from the tart.
Return the tart shell to the oven and bake for another 10-12 minutes until crisp.
Filling: Finely chop the chocolate and add it to a heat-resistant bowl.
Add the coconut milk to a saucepan and bring to a simmer (do not boil).
Pour the hot coconut milk on top of the chocolate and allow it to sit for 5 minutes. Whisk the mixture until smooth, then add in the maple syrup, molasses, ginger, and salt and stir well until evenly combined.
Pour the chocolate ganache into the tart tin and gently tap the tin on your work surface to knock out any air bubbles. Allow it to cool for about 10 minutes before transferring the tart to the fridge to set for 4 hours (or overnight).
Make the vegan gingerbread cookies, if using them.
Garnish: Once set, remove the tart from the tart tin and place it on a serving dish. Top with vegan gingerbread cookies, pomegranate, and fresh rosemary.