Chiffon Cupcake - Vanilla cream filling

My friend asked me for a recipe of this Chiffon cupcake that I made for Remi's birthday. 

Here it is:

Basic Chiffon Cake

Ingredients: 

• 5 egg yolks
• 30 g caster sugar
• 85 g cake flour
• 40 g Milk
• 40 g vegetable oil
• 5 egg whites
• 60 gm caster sugar
• 1/2 tsp cream of tartar

Method: 

1. Preheat oven to 320F, cupcake pan line with cupcake liners.
2. Mix 20 grams of sugar in the egg yolks, beat gently for them to combine. Add milk and vegetable oil, combine well.
3. Sift in cake flour into the egg yolk mixture, little by little. Mix well and set aside.
4. Use a large clean bowl, making sure there’s no water or oil in it. Beat the egg whites with an electric mixer until bubbles form. Add the cream of tartar. After mixing well, add the 60 grams of sugar in three additions, one-third at a time. Continue to beat until stiff peaks form. 
5. Spoon out 1/3 of the beaten egg whites and fold into the egg mixture. Lightly fold in the rest of the beaten egg whites with a spatula, until just combined.
6. Pour into the cupcake liner and bake in preheated oven for about 15 minutes or until a needle inserted and comes out clean. 
7. Remove from the oven and allow it to cool completely on cooling rack.

Vanilla cream filling

Ingredients: 

• 200 g milk
• 50 g sugar
• 2 egg yolks 
• 10 g cornstarch
• 10 g Cake flour
• Few drops Vanilla Extract 
• 100 ml Heavy Whipping Cream

Method: 

1. Beat the egg yolks until it's fluffy and pale.
2. Mix cake flour and corn starch and sift into the egg yolk, stir to combine.
3. Pour milk and sugar in a small pot over medium heat, heat until bubbling. 
4. Pour 1/3 of the milk into the egg yolk mixture and stir quickly to prevent the egg yolk from agglomerating.
5. Pour the batter back to the pot, add a few drops of vanilla extract and heat over medium heat. 
6. Stir the until the batter about to boil and becomes thick. Remove from heat.
7. Place the pot on a big bowl of ice water and keep stirring until the batter cools down. 
8. Cover the pot with plastic wrap and let it chill in the fridge.
9. When the batter is completely chill, whip 100 ml heavy whipping cream and fold in the batter to combine.