Preheat the oven to 375º F. Place oven rack in the middle.
Make the Caramel: Add the sugar in a heavy-bottomed pot or pan over medium-low heat, stirring constantly to prevent any burnt spots. If your caramel looks very lumpy and grainy, don’t worry. Just lower the heat and keep stirring until sugar dissolves and syrup turns deep amber.
Very carefully pour caramel into the flan mold. Using oven mitts as aid, immediately tilt the mold to coat sides. Set aside and let it cool down for about 10 minutes, or until the caramel is hard.
Put the rest of the ingredients into a blender and blend for a 2 -3 minutes.
Pour the custard into the caramel-coated flan mold. Cover with the lid or aluminum foil.
To bake it we are going to use a water bath, a.k.a Bain-Marie. Fill a large roasting pan with about an inch or so of hot water (not boiling). Place the flan mold with custard in the center. Carefully transfer to the middle oven rack, and bake for 60 minutes. The flan will be ready when the center is just set (mixture will jiggle). Set aside and let it cool. Place in refrigerator for at least 2 hours before serving.
To unmold, run a knife around edges and invert onto a large rimmed serving platter.