Next, mix the brown sugar, butter, corn syrup, and salt in a greased pan over medium heat. Stir constantly. When the caramel bubbles, add the baking soda. It will make the caramel fizz up a bit. This is what we want! Take the caramel off the heat. Preheat the oven to 200 degrees Fahrenheit.
1 cup brown sugar, 1/2 cup butter, 1/4 cup dark corn syrup, 1/2 teaspoon salt, 1/2 teaspoon baking soda