Brush 2 seven inch diameter (18cm) sandwich tins with a little sunflower oil or a soft butter and then line with parchment/greaseproof paper.
Turn on the oven to 180C/350/Gas Mark 4.
Add the caster sugar to a large mixing bowl and then sieve the cocoa powder, flour and bicarbonate of soda to remove any lumps. Stir everything together to combine.
175 g self raising flour, 1 tsp bicarbonate of soda, 150 g caster sugar, 2 tbsp cocoa powder
Using the spatula, create a shallow hole in the middle of the dry ingredients and then add the eggs, syrup, milk and oil to it. I fold everything together with a spatula and then use an electric whisk. Blend everything together until they are no dry ingredients lumps and the texture is lovely and smooth.
2 large eggs, 2 tbsp golden syrup, 150 ml half fat milk, 150 ml sunflower oil
Pour the mixture evenly between the two lined trays and pop on the middle shelf. After 25 minutes, test the cake, it should have risen well and be firm but not solid.
Remove from the oven leaving to cool slightly before transferring out onto a wire cooling tray and put to one side while you make the icing.
Add the butter to a mixing bowl and either with a wooden spoon or preferably an electric whisk, beat until lovely and soft.
100 g unsalted butter
Add the icing sugar and sieved cocoa powder to the butter and beat until smooth.
230 g icing sugar, 40 g cocoa powder
Add the milk a little at a time whilst constantly whisking until the icing is soft, fluffy and easy to spread.
2 1/2 tbsp half fat milk
You now how two options; Spread the icing over both cakes and serve them as single layer cakes or spread icing over one cake and then place the second cake on top and spread the remaining icing.