For the Buttermilk Custard, put the unflavored gelatin in a medium microwave safe bowl, add the cold water and stir to combine. Place bowl in microwave and cook for 20 seconds or until gelatin is completely dissolved and mixture is clear. Set aside.

Meanwhile, heat the buttermilk and heavy cream together in another medium microwave safe bowl. Add the sugar and stir until completely dissolved. Cook on high for 2 minutes and stir well.

Add gelatin to the hot buttermilk mixture and stir until completely dissolved. Pour through a fine strainer and fill four to eight small, individual molds*. Transfer to the refrigerator and chill for several hours until set.

For the Blackberry Soup, put the blackberries, zest, orange and lemon juices in a large pot on the stove. Add the sugar and stir. Simmer very gently for 5 minutes until the sugar has dissolved. Remove from the heat and let cool. Once the mixture has cooled, transfer to a food processor and blend until smooth. Pour through a fine strainer, stir in the liqueur. Cover and chill in the refrigerator until ready to serve.

When ready to serve, run a thin, sharp knife around edges of custard containers. Place custards, one at a time into a shallow bowl containing about 1 inch of hot water. Allow container to sit in hot water for 10-15 seconds, then invert onto a shallow serving bowl. Holding container firmly in place, give it a vigorous up and down shake to loosen custard. Repeat several times if needed till custard is released onto plate. Spoon the Blackberry Soup all around and garnish with a single blackberry and a mint leave, if desired.