Heat oven to 190C/fan 170C/gas 5. Work the flour, butter and sugar together with your hands until well mixed, then press onto the base and up the sides of six 10cm fluted tart tins. Put on a baking tray.
Reserve 36 pecan halves and roughly chop the rest. Beat together the eggs, sugar, syrup, vanilla, bourbon, melted butter and chopped pecans, and spoon into the tart cases. Top each one with 6 pecan halves, then bake for 20-25 mins until golden and set. The filling will rise up as it bakes, but will settle back as it cools. You can make these 2 days ahead and freeze for up to 2 months.
If you fancy a double shot of bourbon, serve the pies warm topped with this iced bourbon cream. Beat the whipping cream with the golden syrup and bourbon until softly stiff, then turn into a rigid container and freeze for up to 1 month. Serve straight from the container like ice-cream, or leave to soften for up to 15 mins for a softer, creamy version.