Preheat oven to 250 degrees Fahrenheit.

Spread popcorn on two baking sheets lined with Gefen Parchment Paper.

In a medium saucepan, combine butter, sugar, light corn syrup, and salt. Melt slowly over medium heat, stirring constantly. When mixture comes to a full boil, stir constantly for five minutes to prevent burning.

Remove from heat and immediately add baking soda. Mix carefully, as the mixture will expand when you add it. Pour caramel over popcorn and mix well to coat.

Bake for one hour, stirring every 15 minutes. Optional: Sprinkle with Maldon salt.

Store in an airtight container.