Measure all your ingredients before starting. Caramel cooks quickly and needs attention. Keep everything close to your stove so you can work smoothly and safely without rushing during cooking.

Add granulated sugar and water to a heavy-bottom saucepan. Place over medium heat and let it cook without stirring. Gently swirl the pan occasionally to help the sugar dissolve evenly.

Watch the sugar mixture closely as it cooks. It will slowly turn from clear to a golden amber color. Stay nearby because the caramel can burn quickly if left unattended.

Once the caramel reaches a deep golden color, remove it briefly from heat. Carefully add the butter while whisking continuously. The mixture will bubble, so take your time and stir gently.

Slowly pour in the heavy cream while whisking constantly. The caramel will bubble again and become smooth. Keep stirring until the sauce is silky and fully combined.

Stir in the vanilla extract and fleur de sel. Mix well to balance the sweet and salty flavors. Taste carefully and adjust salt if needed for your preferred flavor.

Allow the caramel to cool slightly before pouring into a heatproof jar. It will thicken as it cools. Store at room temperature briefly or refrigerate for longer freshness.