In a large cooking pot (at least twice the size needed to contain your soy milk), mix everything together and heat on high while stirring constantly.
Bring to a boil (remember to stir constantly!), and the concoction will froth up.
Remove from heat, let the froth subside, and repeat this cycle three more times.
This is why your pot has to be bigger: the frothing would cause a major spill if you used a smaller pot.
Serve and drink while hot.
You can also adjust sweetness in your cup.
Some people may want to strain this, as the ground spices sometimes have some coarse particles.
This is a very nice hot drink, with a definite indian-food flavour, spicy-sweet and rich.
The original recipe using milk also called for a tablespoon of butter for each serving (yuk!), and that was intended to make the drink rich-tasting.
The thicker soy milk already has that thick rich texture, and is much lower in fat content.