Pumpkin Seed Toffee

1 cup brown sugar, firmly packed
2 sticks butter (no substitutes)
12 oz. chocolate chips
1 cup toasted pumpkin seeds
Sea salt

Melt brown sugar and butter in a medium saucepan, stirring constantly until mixture turns amber and registers 300°F on a candy thermometer. (About 12 minutes) Sprinkle half of the seeds on a greased or parchment-lined jelly roll pan; pour hot toffee mixture over seeds and spread to an even thinness. Immediately sprinkle warm toffee with chocolate chips. Wait one minute and then spread chips across the surface. Top with remaining seeds and sprinkle lightly with sea salt. When cool, break into pieces. Freezes well.