Lots of good advice already. Sounds like your son is very very frustrated and needs your help to learn how to communicate his needs in an acceptable manner. Might he be getting his molars in and maybe he is uncomfortable ?? Have you inquired with his pediatrician. Is your son speaking, perhaps you can use a reward system to get him to "use his big boy words" instead of screaming for something. Don't give it - whatever it may be (pancake) - until he uses his big boy words. Keep talking in a calm voice that you will give him the pancake as soon as he asks using big boy words. and then give it to him. Try and work with him before he gets too upset. I think that when toddlers get really upset they forget what upset them but find it hard to settle down. Sometimes toddlers have a change in sleeping habits which causes them to be cranky - does your son take regular naps ?? My oldest son always took two naps well into his KG year while my younger son stopped the two naps a day routine around 3 years old. The older one needed the extra sleep and always fell soundly to sleep plus slept well through the night. Do you think your son is needing more nap time ??

Good luck and hang in there, he won't be two for ever although it may seem like it.