Step 1

In a heavy saucepan, melt together the butter and brown sugar, stirring constantly to prevent sugar from burning on the bottom of the pan.

Step 2

Once the butter and sugar have melted, whisk in the heavy cream until smooth.

Step 3

Cook the sauce over medium heat for 2 to 3 minutes, just until it begins simmering. Continue to stir constantly.

Step 4

Remove from heat and carefully stir in the vanilla extract (mixture will bubble up) and a pinch of salt, if desired (mixture will bubble up for a moment and then subside).

Step 5

Cool to room temperature, toffee sauce will thicken as it cools.