In a medium saucepan, combine 1 cup of granulated sugar and 1/4 cup + 2 tablespoons of water. Stir gently to combine, ensuring all the sugar is moistened.
Place the saucepan over medium heat. Allow the sugar to dissolve completely without stirring. You can gently swirl the pan if needed.
Once the sugar is dissolved, increase the heat and bring the mixture to a boil. Watch closely as it begins to change color.
Continue to cook the mixture until it reaches a deep amber color, about 8-10 minutes. Be careful not to let it burn!
Once the desired color is achieved, remove the saucepan from the heat and quickly add the diced salted butter. Stir until melted and combined.
Carefully pour in the heavy cream while stirring continuously. The mixture will bubble up, so take care to avoid burns.
Stir in 1/2 teaspoon of fine sea salt. Taste and adjust the salt if necessary.
Allow the caramel sauce to cool slightly before transferring it to a heatproof container. Let it cool to room temperature, then refrigerate.
