Silken firm tofu sets up like a custard when it’s mixed with chocolate or other ingredients, sort of a marvel of no-bake baking. Look for silken tofu in the refrigerator case, packed in water in small containers. These must be drained: Poke the peel-off plastic lid with a paring knife and let the water drain out the hole. Or buy the shelf-stable aseptic-packaged silken firm tofu (packed sort of like juice boxes) which doesn’t need to be drained. And you can keep it on hand in the pantry for months, just in case you want one of these desserts, some of the richest in the book.