Bavarian cream requires heavy cream, powdered gelatin, sugar, egg whites, whipped cream and milk. Chiffons also require cream, gelatin and sugar. Mousses requires, again, the three same ingredients, sugar, gelatin and cream.
Mousse is a classically only egg yolks, egg whites, sugar, and chocolate or other flavorings. Bavarian cream is thickened with gelatin, flavored with liqueur, and lightened with whipped...
