The original recipe for this chocolate gateau comes from the French region of Lyons.
It is made with three layers of chestnut flavoured gateau sandwiching cream and chocolate cream with a chocolate glace icing.
Ingredients:   For Gateau

• 115 grams Flour
• pinch of Salt
• 115 grams Butter
• 8 Eggs
• 340 grams Castor Sugar
• 4 drops Vanilla Essence
• 450 grams Chestnuts (cooked and sieved)
• 425 millilitres Double Cream
• 115 grams Dessert Chocolate (finely chopped)
• 2 tablespoons Water
• 1 dessertspoon Castor Sugar
• 6 tablespoons Orange Jelly Marmalade

For Chocolate Glace Icing

• 170 grams Plain Block Chocolate (finely chopped)
• 8 tablespoons Stock Syrup
• 450 grams Icing Sugar (finely sieved)
• 1 teaspoon Salad Oil
• 3 drops Vanilla Essence

You will also need three 20-centimetre diameter sandwich tins.
  Method:   For the Gateau

1. Pre-heat the oven to 190 degrees Celsius.
   
2. Grease the sandwich tins.
   
3. Place a circle of greaseproof paper in the bottom of each tin and grease this as well.
   
4. Sieve sufficient flour and sugar together and then dust the tins with this.
   
5. Sift the flour with the salt.
   
6. Melt the butter over a very gentle heat.
   
7. Whisk the eggs.
   
8. Add the sugar and vanilla essence.
   
9. Continue whisking until the eggs and sugar form a ribbon on itself.
   
10. The eggs and sugar should be quite thick.
    The trick to this is to do it by hand, in a bowl over a pan of hot water.
    
11. Fold in the chestnuts.
    
12. Fold in the sifted flour.
    
13. Mix in the melted butter.
    
14. Divide the mixture evenly into the prepared sandwich tins.
    
15. Bake in the pre-heated oven for 30 minutes.
    

In the meantime, you can prepare the fillings.
  For the Filling

1. Whip the cream until really thick.
   
2. Divide the cream into two portions - 2/5 in one bowl and 3/5 in another bowl.
   
3. Melt the chocolate in the water and allow to cool.
   
4. Add this to the smaller portion of cream.
   
5. Add the sugar to the other bowl.
   

To Finish

1. Once the cakes have baked for 30 minutes, remove them from the oven and allow to cool.
   
2. When the cakes are properly cooled, take each one and carefully split it.
   
3. Cover the lower layer thinly with orange jelly marmalade.
   
4. Spread plain sweetened cream thinly onto the orange jelly marmalade.
   
5. Reshape the three cakes.
   
6. Now use the chocolate flavoured cream to sandwich these three cakes together.
   

For the Chocolate Glace Icing

1. Put the chocolate into a saucepan with the stock syrup.
   
2. Dissolve the chocolate over a gentle heat and once dissolved bring to just on boiling point.
   
3. Remove immediately from the heat and allow to cool.
   
4. Once cool, beat in the sugar one teaspoon at a time.
   
5. Mix in the oil and vanilla.
   
6. Heat the icing slightly and then pour it over the cake while warm.
   

Allow the icing to reach room temperature once more before serving.