Combine frozen berries, lemon juice, sugar, and 1 pinch vanilla in a saucepan and let boil. Let simmer for a couple of minuts before removing from heat
Blend the nuts in a foodprocessor to flour
Blend the dates as well till they are mashed
Combine nut-flour, dates, raisins, coconut, flour, salt, and cocoa in a bowl
Melt 100 g dark chocolate and 150 g butter in a water bath. When melted, add the coffee and stir till it has an even texture and the coffee has dissolved
Add the dark chocolate, berries, and rum to the bowl and stir till the dough has an even texture
Let the dough cool in the fridge while making the butter cream