Process 55g (1/4 cup) caster sugar, cocoa and pecans in a food processor until pecans are finely ground. Add chocolate, 60g butter and egg, and process until mixture forms a paste.
Preheat oven to 220C and line an oven tray with baking paper. Place pastry on tray. Using a 24cm cake pan as a guide, cut out a 24cm round from pastry. Place a 21cm cake pan in the centre of the round, and, using it as a guide, score a 21cm round in pastry to create a border. Freeze tart base until needed.
Quarter pears, then core and cut lengthwise into 3mm-thick slices. Place flour, remaining 1 tablespoon caster sugar and pears in a bowl. Spoon over the vanilla, then, using your hands, toss to coat.
Spread chocolate mixture over pastry within scored round. Place similar-sized pieces of pear, tightly overlapping, over chocolate mixture (you will have some leftover pear). Melt the remaining 20g butter and brush over the pears. Bake tart for 15 minutes, then reduce oven to 190C and bake, covering loosely with foil if the pastry is over-browning, for a further 25 minutes or until pastry is dark golden and puffed. Set tart aside for 10 minutes to cool.
Dust tart heavily with icing sugar, then, using a kitchen blowtorch, caramelise pears. Serve the tart warm or at room temperature with double cream.
We acknowledge and pay respect to the Peramangk and Kaurna people as the traditional custodians of the Adelaide Hills. We also acknowledge the relationship of the Peramangk and Kaurna people to their country. We pay our respects to the Peramangk and Kaurna people past, present & emerging.