Preheat the oven to 180°C (350°F). Line an 8 x 8” square pan with foil or parchment paper, leaving enough overhang to use as a handle. Lightly coat with coconut oil. My friend used a 9 x 9” pan and it still worked.

Using a blender or a food processor, grind the macadamia nuts into coarse powder. In a large bowl, combine the flour, almond meal, nuts, salt, and desiccated coconut; stir to combine dry ingredients.

Use a pastry cutter to cut in the cold butter, working the mixture until the butter has been reduced to pea-size crumbs. Use your hand to knead the butter into the dry mixture. I used a food processor on a slow setting for this whole process.

When all dry ingredients have been incorporated, press the mixture evenly into the bottom of the prepared pan. Bake for 20 minutes, rotating halfway until the crust is just beginning to brown slightly. Mine baked a bit too quickly so I had to reduce the heat of the oven to 150C.

While the crust bakes, whisk together the eggs, sugar, lemon juice, lemon zest, flour, and baking powder.

Remove the hot crust from the oven and pour the custard over the top immediately; return the pan to the oven and bake for 10 minutes.

Sprinkle the remaining 2/3 cup coconut over the custard. Bake for another 10 minutes, just until the lemon topping is all set and coconut flakes are golden brown (If you aren’t using the coconut topping, just bake for 20-22 minutes, until the lemon custard is set at the centre.)

Transfer the pan to a rack and let the slices block cool down. Use the foil to transfer the pastry to a work surface to cut into square slices or bars.

Assuming you have any left over, these slices can be stored, covered in the refrigerator for 2–3 days.