Chocolate and vanilla cake with buttercream. Rocks are chocolate, found them at Walmart and they tasted great and look so real. It was a nice surprise to find the rocks, saved me lots of time! My daughter loves rocks and she learned that some types of rocks form from lava so she wanted a cake that had both. She also loved my previous Hawaii cake and wanted hers to have a beach and water. She is my toughest client! She wanted a mermaid, but I told her I had to stop somewhere! Next time....