Preheat the oven to 150°C/300°F/Gas mark 2
Combine the dry ingredients in a bowl and make a well in the center. Melt together the butter and mollasses. Add baking soda mixed with boiling water, then pour this mixture into the dry ingredients. Mix to a moist but firm consistency.
Drop by tablespoonfuls onto a greased cookie sheet. Bake for about 20 minutes, until brown at the edges. Cool.