1.For pastry, process flour, sugar and butter until coarse. Add egg yolk; process until combined. Knead pastry on floured surface until smooth. Cover; refrigerate 30 minutes. If pastry is too dry, add 2 teaspoons of water with the egg yolk.
2.Grease two 12-hole (2-tablespoons/40ml) deep flat-based patty pans.
3.Roll pastry between sheets of baking paper to 3mm thickness; cut out twenty-four 6.5cm rounds. Press rounds into pan holes; prick bases all over with fork. Refrigerate 30 minutes.
4.Preheat oven to 200°C/180°C fan-forced.
5.Bake pastry cases 10 minutes. Cool.
6.Reduce temperature to 180°C/160°C fan-forced.
7.Combine chocolate, cream and liqueur in small saucepan; stir over low heat until smooth. Cool 5 minutes.
8.Meanwhile, beat egg, egg yolks and sugar in small bowl with electric mixer until light and fluffy; fold chocolate mixture into egg mixture.
9.Divide filling among pastry cases. Bake 8 minutes; cool 10 minutes. Refrigerate 1 hour. Serve dusted with a little sifted cocoa powder.