Make popcorn as directed and transfer to large bowl.
Heat butter, sugar, and corn syrup in a small saucepan over medium-high heat. Cook, stirring, until butter and sugar melt and a candy thermometer combines and begins to thicken and bubble. Remove from heat, and pour over popcorn, tossing to combine.
Spread popcorn mixture on a parchment lined baking sheet and sprinkle with sea salt and fresh rosemary sprigs.
Bake in oven for 20-30 minutes, tossing halfway through.
Cool before serving.
Recipe by DomestikatedLife at https://domestikatedlife.com/2016/02/18/salted-caramel-rosemary-popcorn-an-oscars-party/