Pop 16 cups corn. Put in large paper bag. In a 2 quart bowl:

1 c. brown sugar
1 stick butter
1/4 light corn syrup
1/2 tsp. salt

Microwave 1 1/2 minutes. Stir well. Boil 3 minutes. Stir twice. Remove from microwave. Stir in 1/2 teaspoon baking soda and 1/2 teaspoon vanilla. Stir until foamy. Pour over popcorn in paper bag. Fold top of bag 4 times. Put in microwave 1 minute. Shake microwave 1 more minute. Shake. Microwave 1/2 minute. Shake. Spread on cookie sheet. Cool.