1Preheat oven to 250 deg F. Grease large roasting pan and place popped corn in pan. Sprinkle nuts over top of popcorn (if you want nuts in this). I prefer dry roasted peanuts but you can use nuts of your choice.
2In saucepan, melt butter. Stir in brown sugar, corn syrup and salt. Bring to boil.
Without stirring, boil 4 min over med heat.
3Immediately remove from heat and stir in soda and vanilla. Pour over popcorn in steady stream, stir to coat.
4Bake in oven, stirring every 15 minutes for 1 hour.
Remove and turn out onto wax paper as soon as you remove from oven to cool. (If not it will stick to your pan when cool!)