Place sugar in a heavy, medium-size pot and turn heat to medium high. Stir the sugar until it starts to dissolve and melt.
1 cup sugar
Whisk until the sugar melts and turns a deep amber, but don't let your sugar burn.
Add butter and continue to whisk or stir until the butter is completely incorporated.
6 tablespoons butter
Carefully add the cream once the butter is incorporated, as it will bubble madly. Stir until smooth, then remove from the heat.
3/4 cup heavy cream
Add salt to the finished caramel sauce and stir to dissolve. Pour the caramel into a large liquid measuring cup and then pour it from the measuring cup into jars.
3/4 teaspoon fleur de sel
Seal jars and let cool a bit, then store in your fridge for two to three weeks.
Cut butter into smaller pieces so it melts more quickly and easily.
If you aren't confident, turn your heat down just before you add your butter. This gives you a little more time, though your caramel may not be as thick.
For more tips and tricks, be sure to read the full article above.