Prepare ½ batch of keto marzipan (prepare the recipe with water and not with egg) and set aside.
Cut off thin slivers of orange and lemon peel (only the coloured part, not the white pith) and chop into very fine slices. Grate the rest of the peel from both the lemon and the orange. Soak the peel together with the sultanas, cranberries and flaked almonds in 1 tablespoon rum or brandy. Minimum soaking time: 30 minutes, or overnight.
Preheat the oven to 180 Celsius / 350 Fahrenheit (electric) or 160C / 320F fan.
In a bowl using an electric mixer or in a food processor, blend the eggs until frothy, pale and double the size - about 2 minutes. Add the sweetener, quark or Greek yoghurt, vanilla and butter. Blend until smooth.
Now add the dry ingredients - almond flour, coconut flour, xanthan gum, pinch of salt, allspice and baking powder and blend until well-combined.
Last, stir through the sultana and cranberry mix with a spatula.
Now, transfer the dough onto parchment paper and press into a rectangle ***see notes. Roll the marzipan into a log and place down the middle of the stollen dough.
Lift one side of the parchment paper to fold the dough over the marzipan. Wet your hands and press the stollen into shape, thereby sealing the marzipan into the loaf. Use the image in the post for reference.
Bake for about 40 minutes or until a knife inserted comes out clean. Don't insert into the marzipan bit - that's supposed to stay moist! After about 15-20 minutes check the stollen and cover with aluminium paper once it's golden on top to prevent burning.
Remove from the oven and brush with melted butter while still warm, then dust with powdered sweetener. Let cool completely before cutting. Option to dust with more powdered sweetener once fully cooled.