In a medium saucepan over medium-low heat, melt sugar until liquefied and golden in colour. Carefully pour hot syrup into a 23cm round glass baking dish, turning the dish to evenly coat the bottom and sides. Set aside.
In a large bowl, beat eggs. Beat in condensed milk, evaporated milk and vanilla until smooth. Pour egg mixture into baking dish. Cover with aluminium foil.
Bake in preheated oven 60 minutes. Let cool completely.
To serve, carefully invert on serving plate with edges when completely cool.