How are puffed rice cakes flavoured? I am working on puffed rice cakes, but I can not find how they are flavoured. 

Is the oil sprayed on it and seasoning sprinkled after? Or is an oil-seasoning slurry sprayed, or is it something else alltogether?

But if oil is used, it must be in a very low quantity as it comes under health food category. Kindly help me with this.
Senbei (Japanese Rice Crackers) are made with already seasoned rice paste... However the glaze that makes Senbei attractive is added after the crackers are cooked... This may work for your rice cakes. The "glaze" is simply a combination of low salt soy, and honey which is then dried off in a hot oven after the crackers have been baked.

Could you possibly use a similar process to flavor your crackers?