Grease a 9×13-inch baking dish and set aside.

Melt 2 cups sugar in a heavy saucepan over low heat, stirring constantly, until fully liquefied and amber.

In a large pot, warm remaining sugar and heavy cream over low heat until sugar dissolves.

Slowly pour melted sugar into cream mixture while stirring constantly.

Increase heat to medium and cook until mixture reaches 244°F (softball stage).

Remove from heat and quickly stir in baking soda.

Stir in butter and vanilla until smooth. Let rest 20 minutes undisturbed.

Stir vigorously until thick and matte, fold in nuts, and pour into prepared pan.

Cool completely, then cut into squares.