A method of making a sponge cake which is storable for 30 days at -20.degree. C. without a substantial change in taste and texture includes: providing a rice flour powder composition comprising a pulverized or powdered product of non-glutinous raw rice having an average particle size of 200 .mu.m or less as a main ingredient and being free of wheat flour and any wheat-derived ingredient; forming a fine foam using egg yolks, whole eggs, and sugar; mixing the rice flour powder composition into the fine foam; mixing melted butter or butter substitute into the mixture of the fine foam and the rice flour powder composition to form a dough; and baking the dough to produce a sponge cake.