Make the ganache first as it needs time to cool. Heat the double cream and butter in a pan on a low heat, you want it to be warm, but not so hot you couldn't hold your finger in it. Take it off the heat and add the dark chocolate. Leave for a few minutes, then stir and the chocolate should have melted, if not, pop it back on a low heat until fully melted together. You can also do this in a microwave, put all of the ingredients into a bowl, microwave for 30 seconds, stir, then microwave in 10 second blasts, stirring between each one, until it's fully melted. Set aside to cool and thicken up
Pre-heat your oven to 140C Fan/325F/Gas Mark 3, and line a cupcake tin with cupcake cases
For the cupcake sponge, mix together the butter and caster sugar, ideally using an electric mixer, for 5 minutes until smooth and fluffy
Add the eggs and milk and whisk them in well
Then gently whisk, or fold in, the self raising flour, cocoa powder and baking powder
Divide the mixture between the cupcake cases, and bake them for 25-30 minutes or until a thin skewer inserted in the centre of the cupcakes comes out clean. Put them on a rack to cool completely
Using a cupcake corer, or a knife, make a hole in the centre of the cupcakes. Fill with the ganache, you can do this using a piping bag or a spoon
For the buttercream, mix the softened butter on it's own for a few minutes. Then add the icing sugar, cocoa powder and milk, and mix until smooth. You can do this by hand, but an electric hand whisk or stand mixer with paddle attachment will provide the best results. If the buttercream is too stiff, you can add a little more milk
Spread or pipe the buttercream on top of the cupcakes. Decorate with the Bourbon biscuits and the crushed biscuit crumbs
Store in an airtight container in a cool place and eat within 3 days
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 cupcakes and unsalted butter for the buttercream.
You can use any cocoa powder for the cupcakes 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.
The Bourbon biscuits will go soft after being in the buttercream for a little while, so add them as close to serving as you can.
For more information on how to bake perfect cupcakes, check out my Vanilla Cupcakes recipe!
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.