Combine cake mix, eggs, and oil and beat on medium speed for 4 minutes.
Add mandarin oranges and juice and fold in by hand (so oranges don't get pulverized!)
Pour in 9x13 pan sprayed with PAM. Bake at 350 degrees for 25 minutes. Test for doneness with a toothpick. Remove from oven when inserted tooth pick comes out clean.
Icing: Combine all ingredients together and spread on cake. Refrigerate cake before and after serving.
Cake may be made with 2 eggs and 1/2 cup of water as a substitution for the 4 eggs.