Separate the 5 eggs. Let the egg whites slide into a tall mixing bowl and beat with the pinch of salt until stiff. Refrigerate.
Prepare the juice and zest of half a lemon.
Cut 200 g dark chocolate into small pieces with a knife (do not rub).
In another bowl, mix the flour with the baking powder, the ground nuts and the spices.
In a large mixing bowl, stir the butter and sugar with the mixer until foamy, gradually work in the 5 egg yolks. Stir in the lemon juice from half a lemon and the lemon zest; also about 1 tablespoon of brown rum. Stir in the chocolate chips and only at the very end fold in the egg whites loosely with a wooden spoon.
Immediately pour the dough into a prepared loaf pan and bake in the preheated oven for approx. 1 hour at 180 ° C.
Let the cake cool in the tin and only then turn it out onto a cake plate. If you like, you can dust the finished cake with powdered sugar or cover it with a chocolate icing.
Tip:
The spice cake should have 1 - 2 days to steep so that the flavors can develop nicely.
The grump gives this cake a nice crunch as it doesn`t melt during baking.