Preheat the oven to 140’C fan/160’C conventional. Prepare your tray by greasing with butter and lining with baking paper/parchment paper
Start by placing the pitted dates and boiling water in a saucepan and bring to a boil. Boil until almost all the water has evaporated
Allow the mixture to cool before placing it into a food processor. Blitz until it forms a thick date paste, it shouldn’t be completely smooth
At the same time, prepare the shots of espresso or instant coffee and top it up with milk to produce 275ml of coffee
Place the melted butter, sugar, black treacle, vanilla, and cardamom into a mixing bowl. Whisk till it forms a smooth dark mixture. This will be the wet mix
Then add the coffee and the date paste and whisk once more till incorporated
Place the self raising flour, baking powder and salt in a separate bowl and briefly mix
Sieve this into the wet mix, then whisk once more until incorporated. Finish by folding with a spatula to ensure no dry flour remains
Pour the sponge batter into the tray and use a spatula, palette knife, or the back of a spoon to spread it out into an even layer
Bake for 50-55 minutes or until a tooth pick comes out clean. Allow the sponge to cool in the tray for 10 minutes before turning out on to a wire rack to cool completely. However if serving at the same time, it does not need to cool completely and can be sliced warm