We had a cactus themed party for my son's 5th birthday (because he likes cacti) and this was the cake!

Cake idea and instructions are from the book "Colette's Cakes" by Colette Peters.

White almond sour cream cake with vanilla buttercream. Needles are white chocolate; flower is gumpaste. Dirt is made from crushed chocolate wafer cookies. Flower pot is real.