Preheat oven to 170°C. Grease an approx. 20 cm x 25 cm ovenproof dish and line with baking paper.
Melt the butter and let it cool.
Sift the flour into a bowl, add the sugar and the desiccated coconut.
In another bowl whisk the coconut milk, egg and butter together. Stir in the lemon zest and juice. Add this to the flour mixture and combine. Add the passion fruit pulp and stir.
Transfer the batter into the prepared dish.
Bake for 50 to 55 minutes or until a skewer inserted comes out clean.
Transfer to a wire rack and let it cool. Cut it into squires or slices and dust with icing sugar.