Start by making the pastry. Place the plain flour, icing sugar and salt in a large bowl and whisk to mix. Add the vegan butter and rub it in using your fingers until the mixture resembles breadcrumbs and no lumps of fat remain.
Add the cold vodka (or water) and vinegar and mix; drizzle in a little cold water as needed to bring the pastry together into a ball. Wrap the pastry and pop it in the fridge for 30-60 minutes until it has firmed up a bit.
Once the pastry has chilled, roll it out thinly (about 3mm) on a floured surface. Use an approx 10-11cm cutter to cut out rounds (I use a small fluted tart tin as I don't have a cutter big enough).
Line a 12 cup muffin tray, plus 3 cavities of a second one, with strips of baking parchment - this makes it easy to get the baked tarts out of the tin. Gently press the pastry rounds into the prepared tin.
Re-roll the pastry scraps and cut out more rounds as needed until you have 15 pastry cases.
Place the muffin trays in the fridge for 20 minutes while you preheat the oven to 190°C/170°C fan/375°F/gas mark 5 and prepare the filling.
To make the frangipane, whisk together the ground almonds, plain flour, cornflour, baking powder and sugar. Add the milk, melted butter, vanilla and almond extracts and whisk until smooth.
Place a Tablespoon of mincemeat into each of the pastry cases then spoon a Tablespoon of the frangipane on top, spread it out a bit to cover the mincemeat.
Scatter some flaked almonds over the top of each mince pie then bake for 25 minutes until golden. Leave to cool in the trays for 10 minutes then lift the tarts out of the tin using the strips of baking parchment and place them on a wire rack to cool. Dust with icing sugar before serving.