Players can turn a chocolate bar into chocolate dust by grinding it with a pestle and mortar (members) or a knife, awarding the player with 1 Cooking experience. This is also a slow, yet effective way of making money via the Grand Exchange. Members can make an energy potion by combining harralander in a vial of water and then adding chocolate dust. Members can also brew chef's delight. Chocolate dust can be used on a cake to make a chocolate cake the same way a chocolate bar can be.
Some players with access to the Culinaromancer's Chest in Lumbridge Castle purchase chocolate bars at relatively low prices from the chest and sell them on the Grand Exchange, making a fair profit. However, the bars do not always sell rapidly on the Grand Exchange.
Other players purchase the bars from the Culinaromancer's Chest, thieve cakes from the Ardougne Bakery Stalls, and then make chocolate cakes for sale on the Grand Exchange. This can be a good money earner, as the ordinary cakes are obtained free while chocolate cakes usually sell well. Players doing this also earn Thieving experience for stealing the cakes and cooking experience for making them into chocolate cakes.
When turning the chocolate bar into chocolate dust while in a free to play server, it used to show your character using a pestle and mortar even though the character would actually use a knife because pestle and mortar is a members only item.