Pop the two bags of popcorn and place in a microwave-safe bowl. I wouldn’t use a glass one as it can burn the popcorn. I’ve also seen this done in a paper bag as well.

In a sauce pan, stirring frequently, bring the margarine, brown sugar, and corn syrup to a full boil for 5 minutes. Remove from heat.

Stir the baking soda into the mixture. It will be come foamy.

Pour over the popcorn and mix. (If in a paper bag, shake vigorously.)

Place the container in the microwave on full power for 1 1/2 minutes. Stir (shake), making sure that you are getting the bottom, especially from the center of the bowl.

Place back in the microwave for thirty seconds and stir or shake again.

Repeat for 30 more seconds.

Spread the caramel corn onto a cookie sheet or waxed paper to let cool, then break up and enjoy!