In a large mixing bowl, beat eggs. Add condensed milk, whole milk, and vanilla and continue to beat until smooth. Set aside while you make the caramel sauce.

Add sugar and water to a small saucepan, then mix until well blended. Cook the sugar on medium heat, letting the sugar turn light amber color before stirring. Continue to heat the sugar and stir until the sugar reaches a dark golden color. Remove from heat and immediately pour into the bottom of baking pan, turning the pan as needed to evenly coat the bottom.

Pour egg mixture on top of the caramel sauce in the baking pan.

Place the filled baking pan into the larger pan on the oven rack. Fill the larger pan with boiling hot water to within 1/2-inch of the top of the filled pan.

Bake for 1 to 1-1/2 hours until set and a knife inserted in the center comes out clean.

Carefully remove the flan from the water bath and run a butter knife around the edges to loosen the flan from the pan. Let cool, then refrigerate at least three hours or until ready to serve.

Garnish with whipped cream and berries, as desired.