Soya yoghurt shake

This one is so simple that I don't even think of it as a recipe when I'm making it, but several people have told me they've never seen these before when I've made them so I figure it's worth sharing anyway as they taste pretty great. It works equally well with any flavour of yoghurt of course.

Ingredients:
Sweetened soya milk
Vanilla yoghurt
Chocolate powder (optional)

Preparation:
1) Fill a glass 2/3 with the soya milk.
2) Top up the remaining 1/3 with the yoghurt and stir well. When the mixture is right it should seem liquid but a little thick, like a smoothie.
3) Sprinkle a little chocolate powder on top and it's ready.