Here’s Martha Washington’s “Great Cake” recipe in the exact words in which it was written for celebrating what she called “a true Virginia Christmas” at Mount Vernon. It calls for 40 eggs! For a more manageable (and realistic) recipe, there’s a nice adaptation on the Mount Vernon Web site here.
If you did want to try Martha’s recipe below, Mount Vernon suggests that the cake would most likely have been baked in a medium oven in a large mold so that it would have risen, with the oven’s heat reduced once the cake started to rise and firm.
Take 40 eggs and divide the whites from the yolks and beat them to a froth, start to work four pounds of butter to cream and put the whites of eggs to it a spoon full at a time till it is well worked. Then put four pounds of sugar finely powdered to it in the same way, then put in the yolks of eggs, and five pounds of flower, and five pounds of fruit. Two hours will bake it. Add to it half an ounce of mace, one nutmeg, half a pint of wine, and some French brandy.