Beat the butter and icing sugar together until smooth.
Push the hard-boiled egg yolk through a sieve and stir the raw egg yolk and vanilla into it. Add this to the butter mixture and stir until blended.
Add the flour and salt to the butter mixture and stir until blended. Shape the dough into a disc (it will be very soft), wrap in plastic and chill until firm, about 2 hours.
Unwrap the chilled dough and slice it into 8 pieces. On a lightly floured work surface, roll out each piece into a circle that is just under 1/4-inch thick and line eight ungreased 4-inch removable bottom fluted tart shells with each piece of pastry, pressing the dough into the shell and trimming away excess dough. Chill the tart shells for 30 minutes or until firm.
Preheat the oven to 180°C. Place the tart shells on a baking tray, dock the bottoms of each shell with a fork and bake them for about 18 minutes, until the edges begin to brown a little. Cool the shells before filling.
For the filling, combine the cream cheese and brown sugar using a blender or immersion blender. Add the egg yolks, pumpkin puree, ginger, cinnamon and brandy and blend until smooth. Pour this filling into the cooled tart shells and return to the 180°C oven to bake for about 16 minutes, until the filling has set around the edges, but still has a little jiggle in the centre. Cool that tarts to room temperature before chilling until set, at least 3 hours.
To serve, sprinkle the tops of each tart with a little sugar and use a butane kitchen torch to melt and caramelize the sugar. Serve immediately.
The tarts can be baked and chilled up to a day in advance, but should be brûléed right before serving.