Cake Extraction Machines are part of the A Piece of Cake World Quest and can be found in the cities of Thais (here), Carlin (here), Edron (here), Darashia (here), and Liberty Bay (here). They are each made up of 6 Ventilation Grilles, 4 Stone Tiles, 4 Distilling Machines, 2 Barbecues, 2 Mysterious Machines, 2 Strange Apparatuses (Coils Activated), and 2 Rock (Grate) tiles. You are supposed to lure 200 Cake Golems on the Rock (Grate) tiles in the machine during raids to make them disappear. There is a copy of A Piece of Cake I (Book) available near every extraction machine, which will explain the first stage of the quest to you.