Directions

1. Grease and line a 4 cup capacity cake pan with parchment paper. Preheat the oven to 338°F.
   
2. Put the lemon and orange zests and caster sugar in a large bowl and rub together with your fingertips. This infuses the sugar with the citrus oils. Stir in the flour, cinnamon, salt and baking powder.
   
3. Whisk the olive oil, eggs and orange juice together and beat into the dry ingredients to make a smooth batter.
   
4. Spoon a third of the batter into the loaf pan and scatter over a third of the quince paste. Repeat with another third of the batter and quince and top with the remaining cake mixture.
   
5. Bake for 10 minutes then dot the remaining quince paste over the top. Layering the quince paste should give you pockets of it throughout the cake. Bake for a further 30 minutes or until well risen and a toothpick inserted in the center comes out clean. Leave to cool in the pan.
   
6. Dust the top with powdered sugar and cut into slices. You may serve with slices of fresh orange and a dollop of mascarpone or ricotta.