In a small jug measure the gin, creme de mure and lemon juice. Add the blackberries and, using a cocktail muddler or the end of a rolling pin, squash them to release the juice. Strain through a fine meshed sieve and discard the pulp & seeds. Set aside
Gently melt the chocolate over a Bain Marie. Once melted stir until completely smooth
Cut the butter into small chunks and stir in until fully melted and incorporated
Stir in the cream followed by the alcohol mix
Let cool, cover and transfer to the fridge to firm up for at least 4 hours
Line a small tin or plate with baking parchment. Take teaspoonfuls of the ganache and drop onto the parchment. Place the tin/ plate in the coldest part of the freezer for 1 hour
Remove from freezer and roll the truffles into balls using the palms of your hands. Put the truffles back on the parchment. Wash & dry your hands after rolling a few truffles if your hands get too sticky to roll the remaining truffles well. When all truffles have been rolled into balls return to the freezer for another hour
Melt the remaining chocolate and allow to cool for 5 minutes, then remove the truffles from the freezer
Take a ½ teaspoon chocolate and put it into the palm of your hand. Roll a truffle in the chocolate to coat - take care to ensure the entire truffle is covered. Set aside on clean parchment. Repeat for all truffles. Leave to firm up for 10 minutes (keep the chocolate warm over a pan of hot water)
Sieve the icing sugar into a flat bowl
After 10 minutes roll the truffles in another layer of chocolate, using the same process as before. Roll in icing sugar and leave to dry. Repeat with remaining truffles
Using a fine brush, dust off the excess icing sugar. Take care to work very gently to avoid cracking the chocolate
Store in an airtight container for up to 2 days