Preheat the oven to 160ºc/140ºc fan and grab cupcake cases
Weigh the egg in the shell to confirm it's weight
Beat the butter and sugar in a bowl until combined
Add the flour, cocoa and egg and mix again
Split between the cases - you may make 3-4, depending on the size of the egg.
You want to aim for a case to be 2/3 full - I use a 5cm scoop to portion the cupcakes
Bake the cupcakes in the oven for 30-35 minutes, and then leave to cool fully
Ganache
Whilst the cupcakes are baking, I make the ganache so it has time to set
Add the dark chocolate, milk chocolate (finely chop if its in bar form) and double cream to a bowl
Heat in microwave in short bursts, stirring well each time, until smooth
Leave to sit on the side to thicken to a peanut butter consistency
Decoration
Using your favourite piping tip, pipe swirls of ganache onto the cupcake
Decorate how you want - I used fresh raspberries and freeze dried raspberries
Notes
Weigh the egg you want to use in its shell - I used a medium egg which was 60g. You need to then match the butter/sugar/dry to this weight. If your egg was 70g, I would use 70g butter, 70 sugar, and 50g flour and 20g cocoa
You can use any milk chocolate, I usually use a supermarket own bar (avoiding brands) for a ganache however. I bulk buy this milk chocolate
You can use any dark chocolate as well, but make sure it's 70%+ or higher in cocoa content for the best ganache. I use this dark chocolate