Preheat oven to 450 degrees F. and lightly butter 2 (1-cup) ramekins (4 inches in diameter by 1 1/2 inches high).
In a heavy saucepan simmer apples, brown sugar, cinnamon, and brandy, covered, stirring occasionally, 10 minutes.
In a bowl with an electric mixer beat whites until they just hold stiff peaks. Beat in hot apple mixture and blackberries until just combined.
Spoon mixture into ramekins, mounding it in centers, and run a knife around sides, freeing mixture to aid rising. Bake souffles on a baking sheet in middle of oven until puffed and golden brown, about 8 minutes, and while they are still warm sprinkle with confectioners' sugar. Serve souffles immediately.