A lumped state variables model for heat and water vapor transfer within a sponge cake during the crust/crumb baking period is presented. The crumb was considered to behave like a viscous compressible mixture, the crust to behave like a porous shell. The model enabled to calculate the time profiles of the crumb state variables (temperature, water content and gas pressure) and also the time variations of the crust and the crumb thicknesses. The numerical solution of the model was used for the determination of the cake thermal and structural properties (crust thermal conductivity, gas phase partition coefficient and crumb bulk viscosity) by fitting the simulated baking curves to the experimental ones. (C) 2004 Elsevier Ltd. All rights reserved.