Preheat oven to 180°C (160°C fan forced oven). Line a baking tray with baking paper.
Combine most of the macadamias and dark chocolate. Keep aside extra macadamias for garnish.
Mix with softened butter with the whisk of the hand mixer or food processor until creamy.
Add sugar, salt and espresso powder (or substitute) and stir two minutes. Add eggs one by one and stir one minute.
Knead the dough by combining flour, cocoa and baking powder. To knead the dough, use the hook of the hand mixer.
Knead half of the dough and add the whole macadamia chocolate mix.
Using a heaped tablespoon, place cookie mix onto baking tray and flatten slightly, remembering to ensure there is plenty of room to expand between each portion.
Sprinkle with remaining macadamias.
Bake cookies for about 12 to 14 minutes.
Gently pull cookies off the baking tray and cool on a wire rack. Store in an air-tight container.