Both the souffl? ball and caramelized banana are originated in Beijing and the banana rolls from Hong Kong/ Macau. It depends on how you define "traditional" but the souffl? balls are named after 高力士 (Gao Lishi) so if you've done Chinese history you should know how long that would date back to :P. The banana rolls are a must-buy if you're visiting Macau. All of these are available in Hong Kong (do visit when you've time )
I'm glad they brought back the Lucky Fountain - am definitely getting that!