Tort di Castagne - Chestnut Cake

I have these Chestnuts in the fridge which is quite impossible to finish by some savoury cooking. I remembered I baked this cake once last year. It tasted moist and special, because there's no flour in it, the whole cake is bake only chestnut and other nuts, so it's gluten free. Chestnut is the only nuts carry Vitamin C, although I have no idea the amount of it after cooking and baking. It just give me the idea, it's good... :D

Ingredients :

• 500g Chestnuts peeled
  
• 250ml milk
  
• 170g brown sugar
• 100g melted butter
  
• 6pc egg yolks
  
• 100g chopped almonds (walnuts)
• 100g chocolate chips
  
• 50ml rum or brandy
• 1 pc lemon (juice and zest)
• 6pc egg whites
• some flour to coat the cake tin
  

Methods :

1. Brush the cake tin with some melted butter and lightly flour.
2. Place the peeled chestnuts in the milk with a little sugar (from 170g), bring to boil and simmer for approximately 15 mins until soft.
3. Puree the chestnuts in a food processor (by small amount, it will be easier, alternately you could mash in a big bowl)
   
4. Beat the sugar and egg yolks in a bowl, whisk until thickened. Pour and mix with Chestnuts.
5. Add in the melted butter, chopped almonds, chocolate chips, zest and juice of lemon and rum or brandy and combine.
6. Whisk the egg whites to the stiff peak stage and fold in gently into the above mixture.
   
7. Pour batter into prepared cake tin. Bake at 175C for 50 minutes or until toothpick inserted in center comes out clean. Let cool in the cake tin and run a knife at the side before remove.