There is no one absolute recipe for garam masala. Each continent, each country, each county, region, and household has its own proprietary blend. No two recipes of the spice mix are the same even if they are predominantly made up of the same ingredients. The flavour lies not only in the combination of spices used but also the varying quantities of the spices.
A couple of weeks ago I read a post online where a friend (Guyanese), said that she added cloves to a beef curry she made the other day and was surprised at how well the flavour complemented the curry. Looking at the comments, she was not the only one surprised. There were a few comments suggesting that she also try adding some cinnamon to her curries. And then there were a couple of comments indicating that if you are “in the know” and make your own masala rather than buy, then you won’t be surprised at the inclusion of cloves and cinnamon in the garam masala mix. These latter comments were written in a cryptic manner, an indication of the secrecy with which many households guard their recipes for garam masala, some of which have been passed down from one generation to the next.
