Pre-heat the oven to 160C Fan/180C/350F/Gas Mark 4 and grease and line a 2lb loaf tin
Mix together the butter and caster sugar, ideally using an electric mixer, until light and fluffy
Add the orange extract, eggs and milk and whisk in until smooth
Whisk in the flour, baking powder and cocoa powder until fully combined
Fold in the chopped up Terry's Chocolate Orange pieces
Pour the mixture into the loaf tin and bake for an hour, or until a thin skewer inserted in the centre comes out clean. Leave to cool fully
To make the buttercream, use an electric mixer for the best results. Mix together the butter, cocoa powder and icing sugar until they start to combine, then add the orange extract and milk and mix until smooth. You can add more milk if the buttercream is too stiff
Put it into a piping bag and pipe it onto the loaf cake, or spread on with a spoon or spatula
Decorate with the remaining Terry's Chocolate Orange pieces and some sprinkles too if you like!
Store in an airtight container in a cool place and eat within 3 days
Video
Notes
To make this recipe with plain or all purpose flour, you will need to add an additional 1 + ¾ tsp baking powder.
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.
For the best flavour, make sure to use a good quality orange extract and not an essence. If you can't get hold of orange extract, you can use the zest of two oranges in the sponge. You can't replace it with anything in the buttercream unfortunately, orange juice will Orange juice is not strong enough to get orange flavour in the buttercream, you would have to use a lot and it could make the buttercream sloppy. What I would suggest instead is mixing 100g melted chocolate orange into the buttercream, then adding 1 - 2 tbsp milk to loosen it if it's too thick.
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.