How to make a chocolate geode? Rock candy geode, geode candy, candy geodes are becoming more popular in baking. It is for cakes. In addition to that, it can be for cupcakes and even cookies. Easter Chocolate geode is also becoming a trend. But what are geodes? Geodes are small cavities in rocks with crystals or mineral matters. They form inside the holes where there are hollow spaces of soil. When liquid minerals enter the cavities, they evaporate.