Preheat oven to 325°F (160°C).

Prepare the caramel: In a saucepan, melt sugar over medium heat until it turns into a medium-dark golden brown caramel, being careful not to burn it.

Quickly pour the caramel into the bottom of a pie plate. You can add a few tablespoons of water to help it melt and spread evenly.

In a large bowl, beat the eggs.

Add condensed milk, evaporated milk, and vanilla extract to the bowl with the eggs.

Mix all ingredients well until thoroughly combined.

Pour the mixture into the pie plate over the caramel.

Prepare a water bath: Place the pie plate inside a larger pan.

Carefully pour boiling water into the larger pan, filling it halfway up the sides of the pie plate.

Place the entire setup into the preheated oven.

Bake for approximately 45-55 minutes, or until the center is set but still slightly soft and not liquidy.

Remove from the oven and let cool completely.

Refrigerate for at least 3 hours to allow the flan to set.

Before serving, run a knife around the edge of the pie plate to loosen the flan.

Invert the pie plate onto a serving dish to release the flan.