Turning raw/baking cocoa powder into instant cocoa (Kaba/Nesquik)
The magic emulsifier is probably soy lecithin.

According to Wikipedia: 


  It is used commercially in foods requiring a natural emulsifier or lubricant. In the food industry it has multiple uses: In confectionery it reduces viscosity, replaces more expensive ingredients, controls sugar crystallization and the flow properties of chocolate, helps in the homogeneous mixing of ingredients, improves shelf life for some products, and can be used as a coating.


The magic soluble is probably a hydrochloride:


  Converting insoluble amines into hydrochlorides is a common way to make them water- and acid-soluble