Move a shelf in your oven to about a third up from the bottom and place a large flat baking tray on it. Preheat oven to 400 °F (200 °C) and let the baking tray preheat in there. You will place the muffin pan of tarts on it when you come to bake them in case of any overflow and to radiate the heat better for perfect pastry.

Put the water and ice cubes in a small jug or bowl and set aside.

Put a 12 hole empty muffin pan(or 2 x 6 holes) in the fridge (it must be a metal one) so it gets nice and cold while you make the pastry dough.

To a large bowl or a food processor add the flour, sugar and salt. Mix them up to combine.

Cut the vegan butter into smallish chunks and add it to the flour mixture. Cut it in either with a pastry cutter or by pulsing the food processor. You can also use your fingertips to gently rub it into the flour if you prefer. The mixture should look like coarse bread crumbs when you've finished.

Gradually add the ice-cold water (making sure the ice cubes don't fall in), stirring with a knife or pulsing the food processor until the dough starts coming together. You might not need all of the water. Use your hands to bring the pastry dough together (removing the blade first if using a food processor) and turn it out onto a well floured, clean surface.

Sprinkle the top of the pastry with a light dusting of flour and roll out to just under ¼ inch / 4 to 5 mm thick. Cut out circles that are 4½ to 5 inches in diameter. You can use a cookie-cutter, or a mug or glass or small bowl that is the right size. Cut as many circles out as you can then reroll the pastry and cut more until you've got 12 circles.

Transfer each circle to the chilled wells of the muffin pan. Gently hold them over and let them fall in, carefully helping them get right into the bottom with your fingers. If you get any tears just pinch them together and smooth out. Crimp the edges however you like. I like the traditional rustic, wavy edges on mine rather than a super neat crimp. Return the pan to the fridge while you make the filling, being careful not to knock the soft pastry.

To a medium bowl, add the softened or melted butter (either is fine), brown/coconut sugar and arrowroot powder. Mix them up then add the maple syrup, coconut milk (be sure to give it a really good stir before using so the separated hard cream and water are mixed and combined well), vanilla extract, salt and vinegar. Whisk it all up well. A few small lumps are fine but make sure any big ones are worked out.

Remove the muffin pan from the fridge and add enough raisins to cover the bottom of the tarts. Then add a layer of chopped pecans.

Pour over the saucy filling to about ¼ inch below the top of the crust, then place a pecan half on the top of each one (optional for decoration) and sprinkle some brown/coconut sugar all over the top of each one. This last sprinkle of sugar is what develops the signature crusty butter tart top so don't skip.

Place the muffin pan on the baking tray in the preheated oven and bake for 20 minutes or until the crust is golden and the filling is bubbling, keeping a close eye on them from about 15 minutes of bake time, (especially important if you are using a dark coloured muffin pan). I like to put the oven light on and watch through the glass door. If they start bubbling up a lot and look like they might overflow, or the pastry gets too dark, remove them a bit earlier, but in all my tests (and there were many!) this didn't happen. In a light-coloured muffin pan, it will take the full 20 minutes. Darker muffin pans radiate the heat differently and cook a little quicker so the tarts might be ready a few minutes earlier.

Once done, remove from the oven and let the tarts cool completely in the muffin pan before attempting to remove.