Pre-heat the oven to 160C Fan/180C/350F/Gas Mark 4 and grease and line a 2lb loaf tin
Dissolve the coffee granules into the boiling water and set aside
Mix together the butter and light brown sugar using an electric mixer or a spoon until light and fluffy
Add the coffee and eggs and whisk in until smooth
Whisk in the flour, baking powder and cocoa powder until fully combined
Pour the mixture into the loaf tin and bake for an hour and 10 minutes, or until a skewer inserted in the centre comes out clean. Leave to cool fully
To make the buttercream, use an electric mixer or a spoon to mix together the butter and icing sugar until they start to combine, then add the vanilla extract and milk, and mix until smooth. You may need more milk or you may not need it all, so add it slowly
Divide the buttercream between three bowls. Colour one with pink food colouring, one with purple food colouring and one with yellow food colouring
Spread the buttercream out onto some cling film, spread each colour out in a line directly next to the following colour
Wrap the cling film tightly around the buttercream, creating a sausage shape
Snip one end of the cling film to expose the buttercream and feed the cling film sausage into a piping bag fitted with your chosen nozzle, the snipped end first
Pipe the buttercream onto the loaf cake, or you can spread it one with a spoon adding blobs of each colour alternately
Decorate with the Mini Eggs
Store in an airtight container in a cool place and eat within 3 days
Video
Notes
Make sure all your ingredients (particularly the butter and eggs) are at room temperature before you start baking.
For the best flavour, make sure to use a good quality vanilla extract and not an essence.
I used a baking spread for the cake and unsalted butter for the buttercream.
The coffee intensifies the chocolate flavour - it will not make the loaf taste of coffee. If you want to leave it out, replace the coffee and the boiling water with 1 tbsp milk instead.
You will need to use a professional grade food colouring to get the same colour strength that you can see in my photos. Brands I recommend are Pro Gel and Sugarflair. Colour Mill and Americolor are also good quality brands.
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.