Honeycomb toffee, honeycomb candy, sponge toffee, cinder toffee, seafoam, or hokey pokey is a sugary toffee with a light, rigid, sponge-like texture. Its main ingredients are typically brown sugar and baking soda, sometimes with an acid such as vinegar. The baking soda and acid react to form carbon dioxide which is trapped in the highly viscous mixture. When acid is not used, thermal decomposition of the baking soda releases carbon dioxide. The sponge-like structure is formed while the sugar is liquid, then the toffee sets hard. The candy goes by a variety of names and regional variants.

Dalgona (달고나) is a Korean candy made with melted sugar and baking soda originating from South Korea. It is a popular street snack from the 1960s, and is still eaten as a retro food. When a pinch of baking soda is mixed into melted sugar, the thermal decomposition of the baking soda releases carbon dioxide, which makes the liquidized sugar puff up and becomes a light and crunchy candy once cooled and hardened. Typically, the creamy beige liquid is poured on a flat surface, pressed flat, and stamped using a cookie cutter giving off the image on the candy such as a star or a heart. Consumers try to trim their way around the outline on the snack without breaking the picture as a challenge. Traditionally, if this trimming is completed without breaking the candy, the consumer receives another free dalgona from the seller.