Divide popped corn and nuts into 2 large aluminum roasting pans. In a saucepan mix sugar, butter, syrup, salt and butter extract flavoring. Bring to a boil stirring constantly. Boil 5 minutes. Remove from heat and add soda. Mix well. Pour evenly over corn and nuts in the two roasting pans. Bake for 1 hour at 250-degrees, stirring every 20 minutes. Pour onto waxed paper and cool.
