The inventive waffle iron has two baking sub-assemblies pivotable with respect to each other from an open position and a closed proximate position in which they define a baking chamber. At any position of the baking sub-assemblies between the closed proximate position and the closed offset position thereof, wherein they are offset from each other by a product expansion, a peripheral element of a baking sub-assembly slides along a corresponding peripheral element of the other baking sub-assembly in such a way that the variable volume baking chamber is formed.