Grease and line 2 x 8 inch sandwich tins
Preheat the oven to 375 degrees F, gas mark 4
Sieve the flour, baking powder, spices and cocoa into a bowl
Cream together the butter and sugar until light and smooth
Add the syrup, then the eggs one at a time, beating well to avoid curdling
Stir in the dates or nuts, the angostura bitters and the vanilla essence
Fold in the sieved dry ingredients a little at a time, adding the milk gradually
Pour the mixture evenly into both sandwich tins
Bake for 30 minutes, until a skewer inserted in the middle comes out clean
Set aside to cool