In a 21cm chiffon tube pan
4 egg yolks
40 g caster sugar
¼ tsp salt
50g cooking oil
150g strawberry puree, remove the leaves, cut into small pieces and process till they became puree (I used homemade strawberry jam which already had some sugar, so I cut down the 40g of caster sugar to 20g. As the jam is drier, I also add 50ml of fresh milk or soy milk)
120 g cake flour
1 tsp of baking powder
5 egg whites
40 g castor sugar
½ tsp Cream of Tartar
1) Beat the egg yolks with a balloon whisk or hand held mixer and add in the castor sugar slowly and also the salt. Add in the strawberry puree (or the homemade strawberry jam with the fresh milk). if you want a stronger taste and some colour, you can add in 1 tsp of strawberry paste. It is optional
2) Add in the sifted cake flour and baking powder in 3 batches into the egg yolk mixture. Mix well. Add in the oil and leave it aside.
3) Use a clean bowl, beat the egg whites with the electric mixer until there are bubbles. Add the cream of tartar. Mix well and add in the castor sugar in 3 batches, beating well in between until stiff peaks form.
4) Take out 1/3 of the beaten egg whites and lightly stirred onto the surface of the egg mixture. Be gentle to introduce the meringue into mixture and careful not to let the air escape from the beaten egg whites. Fold in the remaining egg whites gently in 2 batches until all combined.
5) Pour into the cake pan and bake in a preheated oven of 170C in the middle rack for the first 15 minutes, thereafter reduce the heat to 150C and bake for another 45 min (As different oven works differently, check on it occasionally as some need to bake for a shorter time of 30 mins) If the top of the cake browns easily, you can put an aluminium foil to cover the top to prevent the cake from browning further.
6) Remove the cake from the oven once it is baked. Invert the pan immediately and allow to cool completely before unmoulding.
7) Happy baking and enjoy!