Before you start making the caramel, keep everything ready. Cut the butter into small cubes, keep the heavy cream close and ready to be poured, salt and also a strainer to strain the caramel sauce.
Take a flat deep bottom pan (either steel or white color base), pour the sugar and water. Swirl around to moisten the sugar. Place the pan on medium heat and cover the pan with a glass lid.
Don’t stir or swirl the pan, just keep a close eye. It will take about 10 to 12 minutes for the sugar to change color to amber hue. So, remove the lid after 9 minutes so that you can see the color changing. As soon as the color changes, switch off the heat. Keeping your face away from the pan, pour the heavy cream and whisk. It will start to bubble up and then settle down. Drop the butter cubes and keep whisking until the butter melts and it looks smooth.
Finally, add the salt and whisk it once again. Strain the salted caramel into a clean airtight jar. Sprinkle little more salt on top and let the caramel come to room temperature. It will thicken up as it cools down. Refrigerating it in the fridge will thicken it even more.