1 Make the caramel: Melt 2 sticks of butter in a saucepan; stir in 2 cups brown sugar, ½ cup dark Karo-brand corn syrup, and ½ teaspoon kosher salt. Bring to a boil. Boil without stirring for five and a half minutes; remove from heat; whisk in 1 teaspoon vanilla and ½ teaspoon baking soda.
2 Pour caramel over 20 cups of plain popped corn; stir to coat. Spread coated popcorn out on two baking sheets, prepared with nonstick spray.
3 Bake caramel corn at 250° for about 30 minutes, stirring once, until popcorn can be tapped against the pan and is no longer soft. Stir again, and cool on pans. Try to share.