In a small pot over medium to medium high heat, melt butter and sugar until mixture is bubbling . Continue to simmer, stirring constantly, for one minute.
Remove the pot from the heat. Add the cream in a thin stream, stirring constantly. Mixture may bubble violently (or not…)
Return the pot to medium-low heat. Simmer sauce until thick enough to coat the back of a spoon.
Serve warm over ice cream, fruit or cake. Leftovers can be stored in a covered container in the refrigerator.