Preheat the oven to 350ºF.

Butter a 10-inch cake pan and line the bottom with parchment paper.

Combine coffee and water in a small saucepan and stir until dissolved.

Over low heat, add sugar and butter and stir until butter melts. Turn off heat and let mixture cool to room temperature, stirring occasionally. You can transfer it to a bowl to speed it up.

Add eggs and coffee liqueur to butter mixture and whisk to combine.

Sift flour, baking powder and salt directly onto butter mixture and stir to blend.

Stir in chocolate and nuts.

Bake until a tester comes out almost clean, about 35 minutes. Do not over bake or they will be tough.

Cool in pan on a wire rack.

Loosen sides with a knife, turn onto plate, peel off paper, cut into wedges and serve