The roll:
3 free-range eggs
120 g/4.2 oz castor sugar, plus extra for sprinkling/dusting
60 g/2 oz plain flour
1 teaspoon/5 ml baking powder
1 vanilla pod, split and seeds scraped out
The filling:
1 cup/250 ml cream
1 tablespoon/15 ml caster sugar (for filling)
zest of 1 orange
1 tablespoon/15 ml Grand Marnier
3 tablespoons/45 ml pistachio, finely chopped
The topping:
icing sugar for dusting
2 tablespoons/30 l pistachio, finly chopped
Preheat the oven to 180°C/356ºF.
Line a Swiss roll pan (30 x 24 cm/11.8 x 9.4 oz) with parchment paper and grease lightly. Prepare also a similar size greaseproof paper dusted with icing sugar.
Whisk the eggs, vanilla seeds and castor sugar together to form a pale mousse. Sieve the flour and baking powder together, fold into the egg and mix thoroughly. Pour into a tin spread evenly and bake for 12 minutes or until just done and shrinking around the edges.
Remove from the oven and turn out, upside down onto the sugar dusted parchment paper over a cooling rack. Allow to rest for 1-2 minutes before gently peeling off the baking parchment. Then gently and with the help of a clean kitchen towel, roll up the cake and set aside to cool.
When the roll is cooled sufficiently, whip the cream until it holds soft peaks, fold in the sugar and orange zest and add the liqueur and pistachios. Unroll the cake (remove and discard the paper on the inside) and spread with a layer of the cream filling, then re-roll. Serve as soon as possible sliced and dusted with icing sugar and an extra sprinkling of pistachios on top.