In a heatproof bowl add raisins, butter, baking soda and boiling water. Let sit overnight. This makes the raisins plump up. And then add the following to the raisin mixture. (This batter will be very thick.)
Mix well and put into tin cans that have been greased with shortening. (Campbell's large chunky soup size.) This might be a #303, but I am not sure. Fill 3/4 full. This should yield about 6 cans. Bake in a 350 degree oven for 35 minutes, or until done. Remove from oven and let cool for a while before taking the cakes out of the can.