Easy Sponge Candy

1 cup granulated sugar
1 cup dark corn syrup
1 tablespoon white distilled vinegar
1 tablespoon baking soda
melted chocolate (optional)

Cook sugar, syrup and vinegar over medium heat, stirring until sugar melts. Cook without stirring until mixture is very brittle when placed in cold water. Remove from heat and stir in baking soda. Pour into a well greased 9-inch pan. When hard, break into pieces.

Optional: Dip pieces into chocolate and set on wax paper to dry.