Sift the flour, icing sugar and salt into a bowl.
Dice the butter and rub it into the flour mixture until it resembles sand
Make a well in the centre of the mixture and add the egg yolk. Mix until it comes together
Add the milk 1 tbsp at a time until it forms a dough
Knead on a floured surface for two minutes then wrap in cling film and chill in the fridge for 20 minutes.
Roll out on a floured surface until 5mm thick.
Cut into heart shapes with a cutter and place on a baking tray lined with baking parchment.
Cut smaller hearts from the middle of half the biscuits
Chill for 30 minutes in the fridge.
Preheat the oven to 180C, 350 F, Gas Mark 4.
Place 1 tsp jam in the centre of the whole hearts and bake in the oven for 15 minutes until golden.
Allow to cool slightly and place the cut out hearts on top of the whole hearts.
Leave to cool then dust with icing sugar