Method

• To make the sweet pastry - in a large bowl, with a spatula or wooden spoon, mix the soft butter and icing sugar to a cream: then beat in 2 of the egg yolks
• Add the flour and with your fingertips rub the butter mixture and flour together to achieve a crumbly texture
• Add the walnuts and mix to combine
• Add the water and press the mixture together to form a ball
• With the palms of your hands, knead the pastry on lightly floured work surface until it is blended (maximum 30 seconds)
• Wrap in Glad Wrap/plastic wrap and chill for 30 minutes (this helps the dough lose its elasticity)
• Roll the dough between two sheets of baking paper or Glad Wrap and roll to double the size of your slice tin (slice tin 16-18cm long) and cut in half lengthways
• Line the tin  with a sheet of greaseproof paper and place one half of the pastry snugly into it, pressing into place if necessary
• Mix the quince paste with a wooden spoon or spatula to loosen the consistency, then spread evenly over pastry
• Line with remaining pastry, sprinkle with sugar and bake in preheated oven for 20 minutes or until the pastry is lightly golden and firm to the touch
• Cool and enjoy!