170g unsalted butter, melted
2 tbs Frangelico or other hazelnut liqueur
2/3 cup (150g) caster sugar
120g plain flour, sifted
1 tsp baking powder
3/4 cup (65g) good-quality cocoa powder
3 eggs, lightly beaten
1 cup (150g) whole hazelnuts, roughly chopped
120g good-quality dark chocolate, roughly chopped
Shaved chocolate, icing sugar + pure (thin) cream, to serve
1 1/2 cups (225g) plain flour
1/4 cup (25g) good-quality cocoa powder
1/3 cup (75g) caster sugar
75g chilled unsalted butter, chopped
1 tbs sour cream
50g dark chocolate, melted, cooled
Preheat the oven to 200°C.
Grease and line a 24cm x 3cm loose-bottomed tart pan with baking paper.
For chocolate pastry, place flour, cocoa, caster sugar and butter in a food processor and whiz until mixture resembles fine breadcrumbs. Add sour cream, egg and cooled chocolate and whiz again until the mixture just comes together – add a little more flour if the dough is too sticky.
Form dough into a disc, enclose in plastic wrap and chill for 30 minutes.
Roll out the pastry between 2 pieces of baking paper until 5mm thick. Line the tart pan with the pastry, trimming any excess, and prick with a fork. Line with baking paper and fill with baking weights or uncooked rice, then bake for 20 minutes or until pastry is just dry.
Meanwhile, place the melted butter, Frangelico and caster sugar in a bowl and stir to combine. Sift in flour, baking powder and cocoa, then stir to combine. Stir in egg, then stir in nuts and chopped chocolate.
Reduce the oven to 180°C.
Pour chocolate filling into the tart case and bake for 35-40 minutes until a skewer inserted into the centre comes out with a few moist crumbs but no raw batter.
Scatter with chocolate shavings and dust with icing sugar. Serve warm with cream.