1 Heat the oven to 180°C (160° fan) 350°F gas 4. Line a large baking tray with non-stick baking paper.
2 Beat the butter and sugar in a mixing bowl. Sift in the flour and baking powder until combined.
3 Beat in the egg, orange zest and juice and mix to a dough. Shape into a ball, wrap in cling film and chill for 1 hour.
4 Roll out the dough thinly on a lightly floured surface. Cut out stars and place them on the baking tray. Bake for 12-15 minutes until golden. Cool on the baking tray for a few minutes, then place on a wire rack to cool completely.
5 Melt the chocolate in a heatproof bowl over a pan of simmering (not boiling) water. Dip half the bicuits in the chocolate, to coat. Sprinkle with hazelnut praline and leave to set.
6 Sandwich the biscuits together with orange marmalade