Caramel pudding, cooked caramel hardens when it is cold. I have no experience. How do you make caramel?
Put a little water in the wok, melt the sugar in the wok, simmer slowly until the sugar bubbles, be careful not to burn the heat, and add a little water until the sugar water is a little silky. This will not harden, I hope it can help you, and you should try it slowly, because it is a bit difficult to do it without seeing for yourself.