Cocoa's also used to dust candies and cakes. European process cocoa is treated with an alkali, making it milder yet richer-tasting. It's the preferred cocoa for beverages and frozen desserts, and for dusting baked goods. You can often substitute one type of cocoa for the other, but if the recipe includes baking soda, it may be counting on the acid in natural cocoa in order to react. Don't confuse cocoa powder, which is bitter, with instant cocoa mixes, which are sweetened.
Carob powder tends to lump, so mix it into a paste first with a bit of liquid.
Pastry chefs add this to chocolate to thin it, usually so that they can pour a thinner coating on a cake. Since it's made with vegetable oils instead of cocoa butter, it's much easier to work with than ordinary chocolate. It also melts at a higher temperature, so it doesn't get all over your hands when you eat it. The downside is that it doesn't have the rich taste and texture of regular chocolate. Though it's considered to be a beginner's chocolate, it's still a bit fussy.