Preheat oven to 190C fan/210C.

Prep the cassava - make sure to remove the hard stringy centre.

Finely grate the cassava using the smaller holes of a box grater - you should get around 700g. Transfer the grated cassava to a colander and place in the sink. Squeeze the grated cassava vigorously with your hands to get rid of as much liquid as possible - you should end up with 500g. Transfer to a large bowl.

Halve the passion fruits and scoop the flesh into a sieve set over the bowl of grated cassava. Push down on the flesh with a spoon to extract all the liquid. Discard the seeds.

Grease a 20cm cake tin with butter than line the bottom with a circle of parchment. Put 1 tablespoon of the demerara sugar into the tin and shake to cover the buttery sides.

Brown the 80g butter and cool for a few minutes

Add the browned butter, light brown sugar, coconut milk, desiccated coconut, egg, tangerine zest, lime zest, vanilla, cinnamon and ¼ teaspoon of fine sea salt to the bowl of grated cassava. Mix until thoroughly combined.

Spoon into the tin, level the surface, then sprinkle the remaining 2 tablespoons of demerara sugar evenly over to cover. Bake for 1 hour, or until the top is crisp and golden brown. Leave to cool completely, then run a knife around the edge of the cake to release it from the tine - this might be a little tricky, as the sugar will have hardened.

Place a rack over the tin, then flip the cake on to the rack. Remove the parchment, then carefully flip the cake back over so the crunchy, sugary side is on top. Use a sharp serrated knife to slice and enjoy with coffee.