In a medium saucepan, over medium heat melt the sugar. It is important to stir it around constantly so that it doesn't burn. The sugar will brown a bit and turn into clumps and it eventually melts down to a liquid that is amber coloured.
After the sugar is melted, add in the butter and stir until it is combined. Remove from heat and whisk whisk whisk until it is combined. Return to heat once its combined Note: It is normal for the sugar to bubble up when you add the butter in.
Slowly stir in the cream. Let it simmer for 1 minute. Remove from heat and stir in the salt if using.
The caramel will thicken as it cools. Store in fridge for up to 3 months.