Step 1 – Preheat oven to 170C or 150C fan-forced. Grease and line base and sides of a 22cm springform pan with baking paper.
Step 2 – Combine cacao and boiling water in a small bowl. Cool slightly.
Step 3 – Meanwhile, using an electric mixer with the paddle attachment, beat sugar, coconut oil and eggs for 3 minutes or until smooth and thickened.
Step 4 – Combine macadamia meal, bicarbonate and salt in a bowl.
Step 5 – With motor on low speed, beat cacao mixture through egg mixture. Add almond mixture and stir until combined. Spoon batter into prepared pan and bake for 40-45 minutes or until a crust has formed but cake is still slightly wobbly in centre. Stand pan on a wire rack for 10 minutes. Remove sides of pan and stand to cool completely. Remove base of pan.
Step 6 – Chill cake before serving. Sprinkle with extra cacao and serve with berries.