Chestnut purée
Also known as crème de marrons, chestnut purée is a speciality of the chestnut growing areas of France, Spain and Italy. It is typically available in two forms, one plain, the other sweetened with sugar and vanilla (and boy, is it good).
The sweetened version is very useful for dessert making. When folded into whipped cream it makes a decadently rich filling for profiteroles, meringues, cakes, tarts and chocolate cases, and can be churned into ice cream.