In a medium bowl, cream the butter and sugar. Add eggs, one at a time, beating after each. Dissolve the bicarb soda in the hot water, add it to the egg mixture. Stir in the flour and cinnamon until well blended. Finally, stir in the dates and walnuts so they are evenly distributed.
Drop by heaping spoonfuls onto an ungreased baking tray. Bake for 10 to 15 minutes in the preheated oven until golden.