If you have a desert then such dream signifies the unconscious mind of yours. You feel the lack of the positive and sweet experience in your waking life. The dream about dessert could also show that you feel too much of stability in your life and wish some of the chaos. However, if you really like deserts in your waking life, then it simply shows that you wish to have some kind of dessert, therefore you dream about it.
Read more about dreaming of Desert in other dream meanings interpretations.