In a large bowl, combine the apples, raisins, hazelnuts, brown sugar, cinnamon, clove, cocoa, and rum.

Mix all ingredients thoroughly and let stand overnight (approximately 8 hours).

The next morning, the mixture will be quite liquid.

In a separate bowl, whisk together the flour, baking powder, and salt.

Add the dry ingredients to the apple mixture and mix very well until combined.

Grease and flour a loaf pan.

Pour the batter into the prepared loaf pan.

Preheat oven to 350 degrees F (175 degrees C).

Bake for one hour. Check the bread with a wooden toothpick after one hour.

If the toothpick comes out with wet batter, continue baking for a few more minutes, but usually one hour is sufficient.

Remove the pan from the oven and cut around the rim to prevent sticking.

Let the bread cool in the pan for a while, then carefully remove it.

Optionally, line the pan with non-stick baking paper.

If using baking paper, you can lift the bread out immediately and serve it warm.

Serve warm with vanilla ice cream, if desired.