Place the sugar in a non-stick frypan and slowly melt over low heat without stirring. Shake the frypan by its handle to mix but do not stir with a spoon. When the sugar has melted, pour into a 3 litre glass baking dish coating the bottom.
In a large bowl beat the eggs with an electric mixer until smooth. Pour in the condensed milk, evaporated milk, coconut milk, whole milk and vanilla then mix until well blended; about 2 minutes.
Pour the egg mixture over the sugar in the dish. Place the dish inside of a larger dish then set in the oven. Fill the outer dish with water to 3cm deep.
Bake for 1 hour in the preheated oven or until a toothpick inserted in the centre comes out clean. Remove the flan from the water bath and refrigerate until cold; 4 hours to overnight.
To serve run a knife around the edges of the dish to loosen the flan then invert onto a serving dish.