Cream butter and sugar well. Mix spices in the molasses. Stir in the flour after the molasses has been added to the creamed mixture. (You'll find a large wooden spoon the best utensil for this.)
Add the lemon peel and brandy. Stir well. Soak the soda in the water or milk and add.
The dough should be very stiff. Add a little more flour at this point if necessary. Chill. Roll dough paper-thin and cut into whatever shapes you wish.
Bake on greased cookie sheets in a preheated 325° oven until brown. Ornament with icing, if desired.
NOTES : In Denmark these were used as Christmas tree ornaments. They were made weeks before the great day and stored in tightly covered cans.