Take the bowl of a food mixer and add the milk, melted butter and yeast and stir to mix.
Add the sugar and stir again. Add the flour as well as the salt, baking powder and ground cardamom. Add the 1/4 egg, the best way to do this is crack your egg into something to get the weight and then mix it and add 1/4 of it to the dough. For my sized egg it was around 12g.
Using the dough hook attachment on your mixer, mix well until all ingredients are incorporated, you want to knead for at least 5 mins until the dough has come together and is nice and smooth. Cover the bowl with clingfilm and leave to rise in a warm (not hot) place until doubled in size, around an hour.
Turn the dough out to a floured surface and cut into 6 equal sized pieces for me this was around 67g each. Take care that the balls are completely round and uniform in size. Place on baking tray lined with baking parchment with good spacing between them. Leave to rise for another 30-35 minutes.
Gently brush each bun with the remainder of the egg wash and bake in a hot oven (200ºC) for about 8-10 minutes or until baked through – keep an eye on them as they can burn quickly. Remove from oven and cover the tray with a lightly damp tea towel immediately – this will prevent the buns from forming a crust.
When the buns have cooled down completely, cut a ‘lid’ off the buns – about 1½ cm from the top. Scoop out about 1/3 of the inside of the bun and place crumbs in a separate bowl.
Mix the marzipan with the crumbs until it forms a very sticky mass –add the cream at this point to help it along. You want a spoonable, even mixture. Spoon the filling back into the buns, equally divided. Whip the cream with the vanilla sugar until stiff and use a piping bag to pipe cream on all the buns’ tops. Put the ‘lids’ back on and dust with icing sugar.
These are best eaten the day they are made, as they dry out very quickly.