Step 1

Measure out the butter and cream and place them close to the stovetop.  It's important to do this before you start.

Step 2

Pour the sugar and water into a heavy bottomed, 2-quart saucepan and turn the heat to medium-high.  Whisk until the sugar is fully dissolved.

Step 3

Keep the heat on medium-high and bring the sugar syrup to a boil without stirring.  It's crucial that you do not stir the syrup as it boils, as this will cause the sugar to crystallize.  Instead, gently swirl the saucepan occasionally if you would like.  Please be careful, as the mixture is a lot hotter than boiling water.

Step 4

Watching the caramel closely, continue to let it boil, without stirring, until it turns a rich golden brown (between 360-375 F or 182-190 C on a candy thermometer).  Be careful not to let it get too dark, as it will taste burnt, and watch it closely, for the color can change in seconds.

Step 5

Remove the pan from the heat and immediately add the butter.  Whisk it in vigorously until combined, then pour in the cream and whisk again until everything is smooth and blended.  The sauce will bubble and foam up a lot when the butter is added.

Step 6

Pour the caramel into a glass jar and let it cool to room temperature.  The sauce will be runny at this stage, but it will thicken significantly as it cools.

Step 7

Once it's cooled, seal with a lid and store in the fridge for up to 2 weeks.