I made this for my Grandson’s 8th birthday. Vanilla cake with Nutella buttercream and covered with ganache. The ‘lagoon’ was made with mango flavored gelatin! And the volcano was  made from smushing Rice Krispie Treats around a small glass vase, then covered in lots of ganache. Yes, that is dry ice coming out of the top of the volcano! It was super cool 😁