@AMetroid Development isn't linear. Lots of cultures had things at different times and figured stuff out at different paces. Some looked for answers in ways others didn't or had resources others didn't. Thats why Japanese swords exist, bad iron forced the issue. Unless there is some massive technological leap needed for chocolate there is no reason they can't have it in this world.
If you google chocolate you can see that it was something at its core older than you give it credit. Making it solid blocks is really the only issue you seem to have but remember that this isn't exactly like the past of our world. This world made chocolate before other things. You don't even really know the quality of it btw or its composition.
Taken from googles history of chocolate wiki answer.
The history of chocolate began in Mesoamerica. Fermented beverages made from chocolate date back to 450 BC. The Aztecs believed that cacao seeds were the gift of Quetzalcoatl, the god of wisdom, and the seeds once had so much value that they were used as a form of currency.