Put the sugar in a saucepan with a little water and heat to make the caramel.

Once the sugar has melted and turned a hazelnut-brown caramel color, remove from the heat and coat the bottoms of the ramekins with the caramel.

Pour the milk and vanilla extract into a saucepan and bring to a boil.

Beat the eggs with the sugar until frothy, then add the hot milk and mix well.

Fill the ramekins with the custard mixture. Place the ramekins in a roasting pan, add cold water to the pan to create a water bath, and bake in the oven. Check the custard by gently touching it to see if it has set. Once set, remove from the oven and refrigerate. After 10 minutes, run a knife around the edges and unmold the flans from the ramekins.