Preheat your oven to 180C/350F.
Place the sugar into a small saucepan on medium high heat and stir constantly, cooking until the sugar dissolves and begins to caramelize, approximately 8 minutes.
Remove from the heat as soon as it begins to caramelize as the sugar will begin to burn swiftly.
Pour into your flan mold or baking dish immediately and spread across your baking dish as much as possible.
Place the milk, sweetened condensed milk, eggs, egg yolks, vanilla extract, cornflour and heavy cream and blend until well combined.
Strain the custard over the caramelized sugar.
Place a tea towel into the base of a large baking dish and sit the flan dish on top.
Pour enough boiling water in the larger baking dish to reach half way up the sides of your flan dish.
Place in the oven and bake until the custard is only slightly jiggly in the center, approximately 50 minutes.
Remove and allow to cool to room temperature, then refrigerate for at least 4 hours or preferably overnight.
To serve, carefully run a sharp knife alongside the side of the baking dish to loosen the flan.
Invert onto a serving plate and allow the caramelized sugar syrup to run over before pulling your baking dish away.
Serve up immediately.
Dig in!