Preheat the oven to 350°F (175°C). Place a 9-inch round cake pan or flan mold in a large roasting pan.

In a small saucepan over medium heat, add the granulated sugar. Cook without stirring until it turns deep amber, about 6-8 minutes. Quickly pour the caramel into the cake pan and tilt it to coat the bottom evenly.

In a blender, combine the sweetened condensed milk, evaporated milk, eggs, egg yolks, vanilla, and salt. Blend until smooth for about 30 seconds.

Pour the custard mixture over the hardened caramel in the pan. Place the roasting pan in the oven and carefully add hot water to the roasting pan until it reaches halfway up the sides of the flan pan. Bake for 55-60 minutes or until just set.

Remove the flan from the water bath and allow it to cool to room temperature for about 1 hour. Cover and refrigerate for at least 4 hours or overnight. To serve, run a knife around the edge, place a plate on top, and invert quickly.