To make the pastry, measure the flour and icing sugar into a large bowl and rub in the butter with your fingertips until the mixture resembles fine breadcrumbs.
Add the egg yolk and 1 tablespoon cold water and mix until it comes together to form a firm dough.Wrap in clingfilm and leave to rest in the fridge for about 30 minutes. Preheat the oven to 200°C/fan 180°C/gas 6.
Roll out the dough on a lightly floured work surface and use to line a 23cm loose-based fluted flan tin. Prick the pastry all over with a fork, line with non-stick baking parchment or foil and fill with baking beans. Bake blind in the preheated oven for 15 minutes. Remove the baking beans and paper or foil and return the pastry case to the oven for 5 minutes or until it is pale golden and dried out. Remove from the oven and reduce the temperature to 180°C/fan 160°C/gas 4.
To make the filling, beat the butter with the sugar. Add the eggs, maple syrup and vanilla extract and beat well.
Put the tin on a baking tray, arrange the pecan halves over the pastry flat-side down, then pour in the filling. Bake in the preheated oven at the reduced temperature for 30–35 minutes or until set. The filling will rise up in the oven, but will fall back on cooling. Leave to cool, then serve warm with cream or ice cream.
