Hallon cookies recipe - Telegraph 100g caster sugar 1 tsp baking powder 1 vanilla pod 200g cold, salted butter, cut into cubes 100-150ml raspberry jam Mix the flour, potato flour, sugar, baking powder and a pinch of salt in a bowl. Split the vanilla pod lengthways and scrape out the seeds into the bowl. Add the butter and half the egg. Rub with your fingertips until the dough forms a ball. Refrigerate for one hour. Place the dough between sheets of baking parchment and roll out until 1cm thick. Peel off the top layer and cut out hearts with a 5cm cutter and circles with a 4cm cutter. Set half of each type of shape aside. On all the other shapes, cut out smaller hearts and rounds from the centre of each biscuit. Take the shapes with the holes and paint them with egg on the undersides, before pressing them on to the whole shapes. Fill the holes with jam. Put on lined baking trays and brush with the remaining egg. Bake for 10-12 minutes, then cool on a wire rack. You can store these biscuits in an airtight tin for up to two weeks.