From Mrs. Martha Bradley, The British Housewife: or, the Cook, House-keeper’s and Gardiner’s Companion (London, c. 1755): Boil two Pounds of fine Potatoes till they are thoroughly done, taking Care they do not break; take them up, and lay them on a Sieve to cool; peel them, put the pure Pulp into a Mortar, and beat it to a Mash; add a Gill of Sack to soften it, and then drive it through a Sieve.
Melt Half a Pound of fresh Butter, and mix it with this Pulp of the Potatoes.
Break ten Eggs, beat up all the Yolks with three of the Whites, mix these with the Potatoes and Butter, and then add six Ounces of the finest Sugar in Powder; add last of all another Gill of Sack, and Half a Pint of the richest Cream, grate in a third Part of a Nutmeg, and then stir all very well together that it may be perfectly mixed.