An alternative to baking the batter is to spoon silver-dollar-size cakes onto a hot greased griddle or skillet. Cook on both sides until golden brown. – Old Lyme Inn, Old Lyme, Connecticut
In a large bowl, combine the flour, cornmeal, salt, sugar, and baking powder.
Cut in the butter and shortening until crumbly. In a small bowl, beat together the egg yolk and milk and stir into the cornmeal mixture, along with the baking soda dissolved in hot water. Whip the egg white until stiff but not dry and fold into the batter.
Pour into a greased 8-inch square pan and bake in a preheated 325 degree oven for 30 to 40 minutes.