First smash the blackberrys using an ordinary hand patato masher. When at a stage with some lumps and some juice add in two teaspoons of the yogurt and two teaspoons of the sugar, mix well.
Next add the yogurt, the rest of the confectioner's sugar and sugar together in a bowl, then stir. Make sure there is no lumps.
Now layer the mixtures into rubber cupcake cases, add yogurt first then the blackberry suace and finally a small dollop of yougurt on to and finish with a fresh blackberry on the dollop of yogurt.
Place in a freezer and leave to set for two hours. Keep stored in freezer.