Step 1

Preheat the oven to 350°F (180°C/ 160°C fan/ Gas mark 4). Lightly grease 2 x 20cm/8inch round baking pans.

Step 2

Stir the lemon juice (or vinegar) into the milk and set aside to thicken and 'curdle' slightly into buttermilk.

Step 3

In a pot over a medium heat, melt the butter, syrup and coffee (if using) together. Set aside to cool slightly.

Step 4

Sift the flour, cocoa, sugar, baking powder and baking soda into a large mixing bowl and whisk together.

Step 5

Pour the milk and melted margarine mixture over the flour mixture and stir well until it becomes a smooth batter.

Step 6

Divide the mixture between the two prepared pans and bake for 30-35 minutes or until an inserted skewer or toothpick comes out clean.

Step 7

Allow the cakes to cool in the tins for 5 minutes, then turn out onto a cooling rack to cool completely.

Step 8

Meanwhile, to make the icing beat together all ingredients until smooth.

Step 9

When the cakes are completely cold, sandwich together with half of the icing. Spread the remaining icing over the top of the cake.