It was so much fun, not to mention pretty quick and easy, so I thought I'd share the recipe and images. It puffed up so fast we were cracking up, this would be a fun candy to make with kids!
Note: The recipe doesn't include the chocolate dipping. I used a double boiler (2 pots, the bottom one with water to boil, the top with chocolate to melt). I used a 50% milk chocolate, 50% dark chocolate mix.
1 c. dark corn syrup
1 tbsp. white vinegar
1 tbsp. baking soda
1. Combine sugar, corn syrup, and vinegar in a large saucepan. Cook, stirring constantly until sugar dissolves. Cover pan for 1 minute to allow the steam to wash down the sugar crystals that cling to side of pan, or whip down the crystals with a damp cloth.
2. Uncover pan; insert candy thermometer. Cook without stirring until candy thermometer reaches 300 degrees (hard crack stage).
3. Remove from heat; stir in baking soda. Pour into a buttered 9 inch square pan. It's not necessary to spread, as the mixture will bubble and spread itself. Cool in pan on wire rack.
4. Break cooled sponge in pieces. Store 2-3 weeks in a tightly covered container with foil or plastic wrap between layers.(recipe copied from cooks.com)