We don't know who would have a pan big enough to make this, but we just had to share.
Take 40 eggs and divide the whites from the yolks and beat them to a froth. Then work 4 pounds of butter to a cream and put the whites of eggs to it a Spoon full at a time till it is well work'd. Then put 4 pounds of sugar finely powdered to it in the same manner then put in the Yolks of eggs and 5 pounds of flour and 5 pounds of fruit. 2 hours will bake it. Add to it half an ounce of mace and nutmeg half a pint of wine and some fresh brandy.
Notes on making Martha Washington's Great Cake:
In making the great cake, Mount Vernon's curatorial staff followed Mrs. Washington's recipe almost exactly. Where the recipe called for 5 pounds of fruit, without specifying which ones, 2 pounds of raisins, 1 pound of currants, and 2 pounds of apples were used. The wine used was cream sherry. Since no pan large enough was available to hold all the batter, two 14 layers were made and stacked (note: the original was one single tall layer). The layers were baked in a 350 degree oven for 1.5 hours. Should be iced with a very stiff egg-white based icing, flavored with rosewater or orange-flower water.