Add the sugar to a medium saucepan over medium heat, stir continuously with a spatula. It will take about 5 minutes, but it will begin to clump & melt in the pan. Break up any lumps as you see them with the spoon. Stay patient, it will melt!
Once it has melted into a light brown sauce, quickly whisk the room temp butter 1 tbsp at a time.** if your caramel seizes up and hardens, keep whisking over low heat, it may take ~4 minutes but be patient it will come back together. Pick out any hardened pieces that won’t melt back in.**
With butter fully melted & incorporated, very slowly pour in the heavy cream and whisk as you pour. Allow it to come to a boil for about 1 minute & let cool, it will continue to thicken as it cools so transfer to a sealable storage container.
Refrigerate to store & reheat to thin into a ribbon consistency!