Grease and line a 20cm X 30cm baking tin and set aside. Preheat oven to 150 degrees celcius.
Beat sugar, eggs, vanilla essence and milk. Mix well. Then add the dates and coffee & chicory essence and mix well. Turn off beater and with a spoon fold in the sifted flour and baking powder into the date mixture.
Once everything is combined, pour into baking tin and put into the oven for 30 minutes. Once finished baking, allow 30 minutes for the slice to cool down.
Combine the icing sugar, coffee & chicory essence, butter and hot water and mix well. Then pour over the now cold slice and refrigerate until icing is set.
This slice is better eaten a day after it is made.