Chocolate and cocoa are versatile ingredients. They’re incorporated into many mixtures of ingredients, and not just sweets; savory Mexican mole sauces and some European meat stews and sauces borrow depth and complexity from them. Chocolate and cocoa provide flavor, richness, and structure-building capacity; their dry particles contain both starch and protein, absorb moisture, and contribute thickness and solidity to baked goods, soufflés, fillings and icings. Flourless cakes can be made with chocolate or cocoa as the starchy and fatty ingredients, eggs as the moistening and setting agent. In a chocolate mousse, the foam structure provided by the whipped eggs is reinforced by both the dry particles and the gradually crystallizing cocoa butter.