Preheat the oven to 200°C (Fan 180°C).
Grease a 20 x 30cm baking tray and line it with parchment paper. Put the flour, butter and sugar in a bowl and rub them together with your fingers until the mixture looks like breadcrumbs.
Add the beaten egg and vanilla extract, then mix and bring everything together with your hands to form a soft dough.
Wrap the dough in cling film and put it in the fridge for 30 minutes – chilling the dough makes it easier to work with.
Cut one-third off your dough. (Editor’s tip: you may want to pop this dough into the freezer as it will be easier to grate.)
Dust your work surface with flour, then roll out the larger piece to the same size as your baking tray. Carefully transfer the dough to the baking tray, using your fingers to push it into the edges.
Spoon the apricot jam over the dough, making sure you spread right to the edges.
Coarsely grate the smaller piece of dough and scatter it over the jam.
Bake for 20–25 minutes until the top is golden. Remove the tray from the oven and leave the biscuits to cool for 15 minutes.
Cut into pieces while the biscuits are still warm, then put them on a wire rack and leave them to cool completely before eating.
