In a medium to large pot, melt the sugar over moderately high heat. Whisk the sugar as it melts to get even melting and heating.

Keep whisking until liquefied, and the sugar becomes a rich copper color.

Add the butter all at once and stir it in.

Once combined, remove the pot from the heat.

Pour in the heavy cream (the sugar will foam up) and whisk until smooth.

Gently whisk in the chopped nuts.

You can use this sauce immediately or store in an airtight container or jar for up to two weeks in the fridge (mine never lasts that long!). To reheat, uncover and microwave for about 30 seconds.