In a bowl, sift the flour with the cocoa, baking powder, and coffee.
In a saucepan, melt the butter over low heat until smooth. Add the sugar and mix.

Add it to the eggs along with the vanilla and mix. Add all of this to the flour mixture and stir well to form a batter.
Add the raisins and chopped walnuts and mix.

Preheat the oven to 350°F/178°C.
Coat with oil or butter or line with parchment paper a baking sheet pan measuring approximately 17 cm x 24 cm/ 7” x 10”.
Spread the batter on the baking sheet pan and decorate with walnuts.

Bake for about 25 minutes. Once cooked, let it cool completely.
You can cut them into any size you like. I cut them into 3 pieces long by 5 pieces wide, for a total of 15 pieces.