Roughly chop chocolate, place in a saucepan or snow kettle and melt over steam together with butter. Place in a cold water bath and stir until cold.
First stir the blackberry liqueur and sugar into the chocolate mixture, then the eggs, one at a time. Combine almonds and cornstarch and stir into chocolate mixture as well.
Butter a tart pan. Pour in the chocolate mixture and spread the blackberries on top.
Bake the tart at 200 °C for about 25 minutes – it should still be slightly moist. Remove, let cool and refrigerate for at least 3 hours.
Divide into portions and garnish with fresh blackberries, cream and mint leaves.
Preparation Tip:
The mixture is enough for 1 tart 20 cm in diameter.