• Preheat oven to 325 F

For the caramel

• Place the caramel sugar in the cake pan, on the stove over medium heat and caramelize the sugar, making sure it coats the sides of the pan too. Do not over brown the sugar! It will cook a little more when baking the cake.
  

For the cake

• Clean the apples, peel the skin off and remove the core with a sharp knife.
• Mix quince jam and peanuts in a small bowl.
• Place the apples in the pan and fill the cores with the jam peanuts mixture.
  
• Drizzle lemon juice and sprinkle cinnamon powder.
• Make the sponge cake batter. In a large bowl, beat the eggs and the sugar with a hand mixer. Slowly add milk, oil, vanilla and lemon zest and mix well. Mix flour and baking powder. Gradually add flour mixture and mix well.
• Pour the batter between the apples.
• Bake in the middle of the oven for about 40-45 minutes or until the cake top becomes golden (make a toothpick test in the middle, inserting into the batter not the apples; if it comes out clear the cake is done).
  
• Optional step - make a syrup. Mix 2 tablespoons rum extract, 4 tablespoons sugar and half a cup water. Use a spoon to distribute the syrup evenly.
• Place a large plate over the cake pan then turn it upside down. Remove the pan.