Preheat the oven to 200 ° C (top / bottom heat, convection: 180 ° C). Melt the butter and let it cool down a bit.
Beat the eggs with the sugar until frothy, add the orange juice and melted butter and stir everything together. Sieve the flour and mix with the baking powder. Stir the flour, cocoa and shredded chocolate into the egg mixture.
Brush a bundt pan or loaf pan with oil. Pour the dough into the mold and bake in the hot oven (center) for approx. 45 - 55 minutes.
If you want it a little more chocolatier, you can cover the cake with chocolate icing, but the cake tastes very good on its own.