I thought of my mom the whole time I made this candy. I always remember it being her favorite while I was growing up, and now it is one of my favorites as well.
I wish she were here to help me make a batch.
1 c white sugar
4 T white corn syrup
2 t baking soda slightly dissolved into 1-2 teaspoons of water
1 c dark chocolate, chopped into small bits
1. Line a cookie sheet with waxed paper and lightly oil the waxed paper.
2. In a large pot, combine sugar and syrup over medium heat. As the sugar dissolves, turn down heat yet make sure that the mixture keeps to a steady, simmering boil. DO NOT MIX.
3. As soon as the mixture turns a light yellow*, sprinkle in the baking soda mixture. Again, DO NOT MIX! You want to keep the bubbles so the candy remains light and airy. The mixture will bubble up and increase 4 times in volume. Remove from heat and quickly pour mixture onto prepared cookie sheet. It hardens quickly.
4. Melt dark chocolate in a double boiler. When melted, spread over sponge toffee and cool until set. Break sponge into pieces and store well in a tightly-lidded container.
* Do not wait for the mixture to take on a golden hue....or it will be too late. Light yellow is what you're looking for.