01Add sugar, salt and water to large, heavy bottomed saucepan over medium high heat. Let cook without stirring until it turns a deep amber color, about 8 minutes. Remove from heat and slowly whisk in hot heavy cream until combined. Set aside to cool while you prepare panna cotta.
02Pour 1/2 cup milk into large mixing bowl. Sprinkle gelatin over milk and let bloom.
03Meanwhile, combine remaining milk and heavy cream and in large saucepan over medium-high heat. Bring to simmer, remove from heat and whisk into bowl with gelatin. Whisk in vanilla and salted caramel sauce until combined.
04Divide mixture evenly between serving glasses and let cool to room temperature. Refrigerate 2-4 hours, until panna cotta is set.
05To serve, top with whipped cream and caramel popcorn.