SNOW CREAM.

Heating the cream before adding cornstarch-thickened mixture prevents lumping by ensuring even gelatinization of the starch granules. The cornstarch swells and absorbs liquid at 144-180°F, creating a stable, thickened base. Folding in stiffly beaten egg whites while the mixture is hot causes the proteins to set immediately, creating an airy foam structure that's stabilized by the thickened cream base. The brief boil after adding eggs pasteurizes them while setting their structure without curdling.