Line a 1 litre loaf pan (10 × 20 cm) with baking paper.
To make the base, combine the macadamia nuts, coconut, dates and lemon zest in a blender and blitz until the mixture forms a crumbly paste. Add this mixture to the loaf pan, spread it out evenly and press down firmly with the back of a spoon. Pop the base in the freezer while you make the filling.
To make the filling, combine all the ingredients in a blender and pulse until smooth. Pour the filling over the crust and spread evenly. Freeze for 4 hours to set.
Cut the slice into pieces. Let slice sit for 15-20 minutes before serving. Top with freshly grated lemon zest.