1. Preheat the oven to 170C (325F/Gas 3).
2. Line a square 25cm cake tin with baking paper.
3. Combine the flour, ground almonds, cocoa, baking powder in a bowl. Add the macadamia oil, maple syrup, eggs, soy milk, chocolate and walnuts. Mix together well, then pour into the prepared cake tin, smoothing the top level.
4. Bake for 35-45 minutes, or until the cake is cooked through.5. Cool to room temperature, then cut into squares.
Store in an airtight container in the fridge for up to 4 days.
For nut allergies substitute ground almonds for desiccated coconut or ground linseed meal. You can also substitute the macadamia nut oil for a grape seed oil and the walnuts for either dried apricots, sultanas or frozen cherries.