Dissolve the baking soda in the milk and stir together all of the ingredients for the layer. Pour the resulting dough into an oiled and buttered tray or cake form. Bake in a moderate oven.
Dissolve the sugar for the syrup in the hot milk. Invert the baked and cooled cake onto a suitable platter or cake plate, poke it with a fork in several spots and pour on the syrup.