Crumble the digestives in a food processor, add the melted butter and mix well. Place in a 20cm flan ring with a push-up base, or individual mini rings and pat down with the back of a spoon. Melt the white chocolate in a glass bowl set over a pan of simmering water. Mix the cream cheese, cream and sugar together in a medium sized bowl until smooth. Quickly add the melted white chocolate and fold through. Next, arrange the raspberries over the biscuit base, reserving a few to decorate the cheesecakes. Spoon the cream cheese filling into the prepared rings and smooth the top with a palette knife, being careful not to squash the raspberries. Place in the fridge and chill for 2 hours. Serve decorated with more raspberries and mint leaves dusted with icing sugar. Remove the flan ring and serve.