Ingredients
450g blackberries
140g golden caster sugar
2 egg whites
250ml tub mascarpone
To decorate
142ml tub double cream
100g blackberries and leaves
icing sugar to dust
Method
Put the blackberries in a pan with one rounded tbs of sugar; gently heat until the juices run. Simmer for 5 mins until the berries are just soft. Press through a sieve into a bowl and leave to cool.
Put the egg whites in a bowl with the remaining sugar and set over a pan of simmering water. Whisk until the meringue is marshmallowy (3 mins). Take off heat; whisk for 2 mins. In a bowl, beat the mascarpone with a wooden spoon, then beat in the puree. Fold in half the meringue, cutting through the mixture; fold in the rest. Turn into a serving bowl; chill for 1 hour.
Just before serving, whip the cream until it just holds its shape; spoon over the mousse. Scatter with fruit and the leaves, if using. Dust with icing sugar.