The present invention provides a method of making a puffed food starch material product. A food starch material capable of volumetric expansion in three dimensions is placed into a puffing chamber. Expansion of the food starch material includes constraining expansion of the food starch material in at least a first dimension while permitting unconstrained expansion of the food starch material in a second dimension to produce a unitary, puffed food starch material product with at least one surface having a wavy contour. In a method of making a puffed food starch material product of the present invention, a puffing chamber is provided having inner surfaces and a chamber volume. A bulk amount of the food starch material is placed into the puffing chamber. The bulk amount of food starch material is caused to volumetrically expand. The expanding food starch material is constrained in its expansion in at least a first dimension, while permitting expansion of the bulk amount in at least a second dimension.