The name given to a sweet, rich, flat cake made chiefly in Lancashire, to be eaten on Mid - Lent Sunday. The name Simnel is derived from the Low Latin siminellus- bread made from simila wheat-flour. The following is a good receipt for its manufacture:
Beat 1lb of butter with the hand till creamy, then add the well-whipped whites of six eggs; beat these together for a minute, then mix in the beaten yolks of the six eggs, 3/4lb of caster sugar, 1 1/4lb of flour,1 1/2lb of well-washed and dried currants, 3/4lb of finely -shred candied citron and lemon peels, 1/2 lb of blanched and chopped almonds, 2oz of orange-sugar, and ½ oz of pounded nutmeg, cinnamon, and allspice. When the above ingredients are well mixed, pour in 1 wineglassful of brandy and a little water, and beat them for some time. Gather the paste into a lump, then roll it out, double it over, put into a cloth that has been wrung out in hot water and floured, tie it up, put in a saucepan of boiling water, and boil for three hours. Take the cloth off the cake at the end of the three hours, stand the cake on a tin, the smooth surface upwards, and leave it till cool. Brush the cake over with a paste brush dipped in beaten egg, and bake in a slow oven till the outer crust is hard and lightly browned. Take the cake out, and leave it till cold.
~Garret, Theodor Francis, 1899, The Encyclopædia of Practical Cookery