Pre-heat the oven to 160C Fan/180C/350F/Gas Mark 4 and grease and line a 2lb loaf tin
Mix together the butter or baking spread and caster sugar for around 3 minutes until light and fluffy, ideally using an electric mixer
Add the eggs and milk, and whisk in until smooth
Whisk or fold in the self raising flour and cocoa powder gently until fully combined
Pour the mixture into the loaf tin and bake for an hour, or until a skewer inserted in the centre comes out clean. Leave to cool fully
To make the buttercream, mix together the butter, cocoa powder and icing sugar until they start to combine, then add the milk, and mix until smooth. You can add a little more milk if the buttercream is too stiff. Use an electric mixer for the best results
Put the buttercream into a piping bag and pipe it onto the loaf cake, or spread on with a spoon or spatula
Decorate with dark chocolate curls if you like. I use a potato peeler to shave a bar of dark chocolate to create the curls
Store in an airtight container in a cool place and eat within 3 days. Or you can freeze it for up to 3 months
Video
Notes
Make sure all your ingredients (particularly the butter and eggs) are at room temperature before you start baking.
I used a baking spread for the cake and unsalted butter for the buttercream.
You can use any cocoa powder for the cake and buttercream, of course the better quality it is, the better flavour they will have. Do make sure you are using cocoa powder and not a hot chocolate powder.
You will need a 2lb loaf tin for this recipe (you can test the size of your loaf tin by seeing how much water the tin can hold, 2lb will hold about 2 pints/1100ml of water). If you have a 1lb loaf tin, simply halve the ingredient amounts.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50) .
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.