Preheat the oven to 180°C/160°C fan/350°F/gas mark 4. Grease a 20 cm / 8 inch square cake tin and line it with baking parchment.
Chop the marzipan into 1-2 cm dice, spread it out on a tray and pop it in the freezer while you get on with making the dough.
Whisk together the caster sugar, melted vegan block butter, non-dairy yogurt, orange extract, almond extract, glycerine, mixed spice, ground cardamom and salt in a large bowl until well combined.
Whisk in the ground almonds and baking powder then stir through the dried cranberries, sultanas and roughly chopped pistachios.
Add the bread flour and stir until it is well combined and no dry paches remain, it should be a very soft dough or extremely thick batter consistency. Fold through the frozen marzipan.
Transfer the dough to the prepared tin and spread it out firmly and evenly, pressing it right into the corners. If you are struggling to do this, you may find it easier to wet your hands and spread it out by hand.
Bake for about 40 minutes, until it is golden brown and firmish to the touch. If you can find a spot without any marzipan then a skewer should come out clean. Bear in mind that if it goes into a piece of marzipan it will come out sticky however so it is a bit tricky to judge!
Leave the stollen to cool in the tin for 20 minutes then brush it very generously with the melted butter. It may look like too much butter but keep going and use all of it! It helps to keep the stollen moist.
Leave the stollen to cool in the tin completely then wrap it tightly in tin foil and store at cool room temperature.
When you are ready to serve it, brush the stollen with a bit more melted butter and dust it with a thick layer of icing sugar before using a sharp knife to slice it into bars or squares.