Melt the plain chocolate in a heatproof bowl set over a pan of simmering water. Leave to cool a little.
Lightly beat the egg yolks and then whisk into the melted chocolate until well combined.
Whip the cream in a bowl until you have achieved soft peaks and then whisk into the chocolate mixture.
In a separate bowl, beat the egg whites until stiff and then fold into the chocolate mixture.
Divide among 6 x 200 ml/7 fl oz round teacups that have been lined with cling film.
Chill for at least 2 hours or overnight is best.
When the chocolate mousse has set, melt the Mars bar in a small pan.
Remove from the heat and fold in the cornflakes.
Leave to cool a little and then add a layer to each chocolate mousse to form a crunchy base.
Place in the freezer for at least 2 hours or up to one month is fine.
To make the chocolate shards, melt the plain chocolate in a heatproof bowl set over a pan of simmering water.
Repeat with the white chocolate in a separate bowl.
Leave to cool to room temperature.
Line a baking sheet with cling film.
Spoon on blobs of the plain and white chocolate and then cover with another piece of cling film.
Gently roll until the chocolate blobs meet and form one even layer.
Place in the freezer for at least 10 minutes or up to one month is fine.
To make the chocolate ganache, place the chocolate and cream in a pan and cook gently for 1-2 minutes until melted, stirring.
The consistency should coat the back of a wooden spoon.
If you think it is too thick, add a little more cream.
Leave to cool and use immediately or transfer to a bowl, cover with cling film and chill until needed.
This will keep happily for two days in the fridge.
When almost ready to serve, warm the the chocolate ganache in a heatproof bowl set over a pan of simmering water.
Invert the teacups on to a wire rack set over a clean tray and then carefully peel away the cling film.
Ladle a little of the chocolate ganache over each one until completely coated, allowing the excess to drip on to the tray below.
Using a spatula, scrape the excess chocolate ganache into a small pan and reheat gently.
Leave to a cool a little.
To serve, using a fish slice, transfer the coated chocolate mousses on to serving plates and leave to defrost at room temperature for 10 minutes, then decorate with the strawberries and raspberries and drizzle around the cooled chocolate ganache.
Now working quickly, remove the sheet of chocolate shards from the freezer and peel away the cling film, then break into shards and stick two into the top of each Dunbrody Kiss.