Chocolate orange 2 tier chiffon cake

This is the first time I've made a chocolate chiffon, it's as expected, not as soft and light as the fruity and vanilla flavoured ones due to the addition of coco powder. However, it is still soft and does feel like it has a better crumb. For the 2 tiers, use a 23 and and an 18cm round baking tin and fill each tin about 1/3 of the way and equally divide the remaining batter into the two tins up to 1/2 way

Ingredients 

• 125g self raising flour
• 20g coco powder + extra for dusting and truffles 
• 120+50g caster sugar (put them in separate bowls)
• 2 large oranges
• 4 large egg yolks
• 5 large egg whites
• 1 tbsp baking powder
• 70ml vegetable oil
• 100g+50g plain chocolate, cut into small pieces and put in 2 separate containers (50-70% coco)
• 300ml double cream
• 50g muscovado sugar 
• 30g white chocolate 
• Punnet of raspberries (about 200g should be enough, but it depends on how you decorate)

1. Pre-heat fan assisted oven to 170 degrees C
2. Grease a 23 and an 18cm baking tin with butter, DO NOT line with parchment paper
3. Sift flour, coco powder, 120g caster sugar and baking powder together in a large mixing bowl and give it a mix with a metal spoon
4. Add finely grated orange zest and juice from 1 whole orange to the dry ingredients, we need 100ml (if this is not quite 100ml, don't worry, as long as it's more than 80ml, you can add water to make it up to 100ml)
5. Add oil and egg yolks to the batter and mix with a metal spoon until the mixture is smooth and slightly runny (if the batter is stiff, add a tbsp of water and mix again, repeat until you get a runny consistency and the batter runs off the sides of mixing bowl)
6. Beat egg whites in a separate clean bowl with electric whisk until foamy and add 1 tbsp of the 50g caster sugar at a time until the meringue is glossy and forms firm peaks peaks 
7. Fold in 1/4 of meringue into the cake batter and mix until all has incoporated and distributed evenly
8. Add half of the remaining meringue and gently fold it in, once that is done, add in the rest and again gently fold it in until everything has incorporated and evenly distributed and you can no longer see any white streaks in the batter 
9. Pour batter into the 2 prepared baking tins, fill them both 1/3 of the height and distribute the rest between the tins. Make sure you do not fill over 1/2 way as the cake will rise quite a bit and we have to turn the tins upside down to cool
10. Bake for 55-60 minutes for the 23cm tin and the smaller one may only need 40-45 minutes. Check after 40 minutes and see whether cake is done with a sharp knife or skewer and they should come out completely clean
11. Take the sponges out of the oven and turn them upside down on a wired rack and let them cool for at least 30 minutes in that orientation (the cakes are very soft and will most likely collapse on themselves if you left them to cool down the right way up)
12. Use a sharp knife to cut round the edges of the cake and lift them out of the baking tin carefully and cool on a wired rack
13. Cut the sponges horizontally with a sharp knife and divide both sponges into 2, creating 4 layers
14. Whilst cakes are cooling, prepare the filling by whisking 100ml double cream until stiff
15. Mix 1/4 of juice from an orange and 20g icing sugar and fold it in to the cream 
16. Melt 50g  plain chocolate over simmering water, and let it cool slightly and fold it in to the orange cream
17. Spread the chocolate orange cream between each layer of sponge 
18. Make ganache by heating muscovado sugar, 3/4 of juice from an orange and 200ml double cream together until boiling and take it off the heat and let it cool for 2-3 minutes 
19. Add hot cream to 100g plain chocolate and mix with spoon until chocolate has melted and becomes glossy and let it cool for 5 minutes
20. Add chocolate ganache over the top of the cake and spread it evenly over the top, don't worry about the side for now
21. Let the ganache cool for another 30 minutes and it should become slightly thicker, spread it across the side of the cake to make a smooth surface
22. Put the remaining ganache in the fridge
23. Wash and drain raspberries and chop them in half and decorate the sides and top of the cake
24. Melt white chocolate over simmering water and let it cool for 5 minutes and pipe lines across the cake for decoration, create feathering effects with the back of a knife or a skewer by running perpendicular to the white chocolate on plain chocolate ganache
25. Once the ganache has been chilled and firm enough to roll, make balls of ganache and dust with coco powder and decorate the top of the cake to finish 

Tips

• The tins were greased but not lined, this is important, as the baking parchment will prevent the cakes sticking to the side of the tins and let it fall out of the baking tin when turned upside down, hence allowing the cake to collapse. Simply run a knife around the side of the tin and the cake should lift out of the cake tin quite easily
• This recipe can be applied to other fruits as well as long as you are using the juice (and zest if you are doing citrus fruits, e.g. it also goes really well with lemon) and not fruit puree, and you are confident that the flavour of your fruit of choice will not disappear or change drastically during baking