Passion Fruit Chiffon Cake with Passion Fruits Butttercream

For Cake 
Ingredients : 8" round cake pan
5 egg yolks
20g caster sugar
40g corn or sunflower oil  
1/8 tsp salt
60g cake flour
30g rice flour 在来米粉/粘米粉
70g passion fruits juice (without the seeds)
1 tsp homemade vanilla extract 


5 egg whites
50g caster sugar
1 tsp lemon juice or vinegar 



Method :
1. Sift cake flour and rice flour twice.
2. Mix egg yolks and sugar in a bowl, whisk till sugar has dissolved.
3. Add in oil, salt, vanilla extract and passion fruits juice and mix well.
4. Sift in flour mixture and whisk well.
5.In another bowl, beat the egg whites and lemon juice/vinegar till frothy. Add in sugar gradually and beat until approaching stiff peaks (meringue stand straight with a little curve at the tip) or till stiff peaks (this stage is a bit difficult to fold with egg yolk mixture).

6. Use whisk to loosen the egg yolk batter a bit, then take 1/3 of meringue and use a hand whisk to mix well with egg yolk batter.

7. Fold in 1/2 of meringue and use a silicone spatula, gently fold with egg yolk batter till slightly combined. Fold in the balance meringue and gently fold till well combined.
8. Pour the batter from a considerable height into cupcake cases, lightly shake it left and right to level the cake, then gently bang the cupcakes on the table top to release air bubbles.

9. Bake at pre-heated oven at 100C  at center rack for 25 mins. Then adjust to 160C for 15-20 mins. (I off the top heat element and on it back during the last 15-20 mins)

10.  Remove the cake pan from oven, drop it from high side to prevent the cake shrink too much during cool process.
11. Turn the cake pan upside down and cool completely before remove from the cake pan.


Butter Cream Fillings and Frosting:
450g buttercream
90g passion fruit juice (4 passion fruits)
3 tbsp passion fruit juice with seeds