Cocoa roasting reaction notes.
The Maillard reaction:
At high temperatures it transforms flavour and taste precursors into delicious compounds that makes chocolate to what it is. Basically it makes sugars and amino acids form complexes with these precursors. The amount of formed flavors and tastes that are based on parameters such as temperature, pH, time, fermentation, origin, cocoa variety and harvest year.
It never gets boring finding the optimal process for chocolate.