Grease and line a 20x20 cm square baking tin. Preheat the oven to 170°. Cream the butter and icing sugar with a stand mixer or electric beater until pale and fluffy. Beat in the vanilla and egg. Fold in the coconut and sifted flour .Press evenly into the base of the tin and bake for 10-12 minutes. Remove from the oven.

Meanwhile, whisk together the ingredients for the filling. Pour over the top of the base and bake for 12-15 minutes or until set to touch. Remove from the oven.

Meanwhile, beat the egg whites to soft peaks, gradually adding the castor sugar as you go. Fold in the coconut thread, salt and vanilla essence. Gently spread over the top of the passionfruit layer. Bake for 10 minutes.

Remove from the oven and place in the fridge for at least 3-4 hours to cool completely

Cut with a sharp knife into squares.

Keep in the fridge in an airtight container.