Rinse and clean raspberries and blackberries, pat dry. Soak gelatine in cold water. Combine 200 grams (approximately 7 ounces) of each raspberries and blackberries with 50 grams (approximately 1.7 ounces) of sugar and strain through a sieve. Squeeze out gelatine, heat in a small saucepan with 4 tablespoons of raspberry juice and dissolve. Add blackberry liqueur to half of the puree, add gelatine mixture and mix well. Beat cream until stiff and fold. Pour mixture into serving ramekins and refrigerate for at least 4 hours.
Combine the other half of fruit puree with 2 tablespoons of raspberry juice. Before serving, dip fruit mousse ramekins into hot water and invert onto small plates, drizzle with fruit puree and garnsih with remaining raspberries and blackberries. Serve.