Prep. Line two baking sheets with parchment paper (or wax paper). Toast nuts at 350°F for 6–8 minutes, cool, then chop.

Warm cream base. In a large heavy-bottom pot, combine heavy cream, 4 cups of the sugar, and salt (optional). Heat on low, stirring until the sugar dissolves and the mixture is steaming. Keep it on low.

Caramelize sugar. In a separate heavy saucepan, add the remaining 2 cups sugar in an even layer. Heat over medium-low until melted and deep amber, gently moving the pan as needed to melt evenly.

Combine. Slowly pour the caramelized sugar into the warm cream mixture while stirring continuously. Keep stirring until smooth.

Cook to temp. Increase heat to medium and simmer, stirring occasionally, until the mixture reaches 244°F on a candy thermometer.

Finish off heat. Remove from heat. Stir in baking soda (it will foam). Add butter and vanilla; stir until the butter melts and the mixture is smooth.

Rest. Let the mixture rest 15–20 minutes to thicken slightly.

Add nuts. Stir in toasted nuts. Continue stirring until the candy thickens and loses some shine.

Drop and set. Drop spoonfuls onto prepared parchment. Let set at room temperature 1–2 hours until firm.