It is really easy, so here we go:
2 tbs vanilla sugar
a pinch of salt
360g flour 405
20g whole wheat flour
12g (approx.) baking powder
add a bit of milk so that the dough gets elastic (a few tbs should do)
Butter 5 half-litre-glass jars (must be suitable for baking in the oven!) and put half of the dough into them making sure the rim is completely clean.
Heat the oven to 175-180°C.
Add 20g cocoa powder and
a spoonful of dried cherries or cranberries to the rest of the white dough, mix and fill into the jars (attention: do not fill them too high as the dough will rise notably in the oven!)
Bake the cakes for about three quarters of an hour.
When they are done, take them out of the oven and close the jars immediately. While cooling they should seal hermetically and will stay fresh for weeks.
Once you want to serve them, just dust them with some icing sugar. Serve with a generous cup of hot chocolate.