Preheat oven to 180°C/ 350°F/ Gas Mark 4. Grease and flour a nine-inch by thirteen-inch baking tin. Sift flour with salt and baking powder. Beat eggs well.
Beat in honey gradually. Add vanilla essence and mix. Add the flour mixture to honey mixture and mix. Stir in dates, walnuts and oil. Mix well and pour the batter into the prepared tin.
Bake in the preheated oven for about thirty minutes. When cool cut the cake into bars. Roll in icing sugar. You may wrap the bars individually in butter paper or aluminum foil.