1 cup butter
1 cup brown sugar
1 tsp salt
1/2 cup syrup (Light Karo)
Mix these ingredients on stove top on medium heat. Stir until it boils. Let boil for 5 minutes with no stirring. Turn off burner and add:
1 tsp vanilla
1/2 tsp. baking soda
Pour over 6 quarts of popped corn that is in a large aluminum roaster.
Bake for 1 hour at 250 degrees, stirring every 15 minutes.
Spread out on two cookie sheets lined with wax paper until cool. Store in large ziploc bags or air-tight container