Chocolate Soufflé Cake

After baking the cottony, soft and moist Orange Soufflé Cake, I was all excited to try this cake with a different flavour.  Promised myself, I will try to bake this cake again without any mistakes.  So here is my Chocolate Soufflé Cake.    The cake rose beautifully but shrinks a little because it is low in gluten.   The cake is really soft, moist and cottony.   Probably will try to bake another such cake using lemon.
Ingredients

3 egg yolk
1/2 egg (about 30g)
15 gm sugar [I used 1 tbsp]
1/4 tsp salt
50 ml chocolate milk [I used 2 tsp cocoa powder mix with 50 ml hot water and 1 tbsp condensed milk] - cool before use
 35 ml vegetable oil [I  used 1 1/2 tbsp]
1/4 tsp chocolate paste
40 gm cake flour  - sifted - set aside
3 egg white
55 gm sugar [used 3-4 tbsp]
1/4 tsp cream of tartar

1. Line base of a 7" square tin with grease proof paper and wrap it with tin foil.  Place it in a bigger square baking tin.  Preheat oven to 150C.
2. Mix chocolate milk, oil and chocolate paste together.
3. Use a hand whisk mix egg yolks, half egg, sugar and salt together.
4. Add in liquid mixture and whisk until well combined.
5. Fold in sifted flour and stir until batter is smooth.
6. Use a cake mixer, whisk egg whites and cream of tartar till frothy.   Add in the sugar in 3 batches and whisk until soft peaks formed.
7. Fold in 1/4 of the meringue into the egg yolk mixture until combined.   Then fold in the rest of the meringue lightly in two portions until well combined.
8. Spoon 1 Tablespoon batter and mix with 1 tsp chocolate paste.  Mix well.
9. Pour batter into prepared cake tin.  Place it in the bigger cake tin.  Drop a few drops of the cocoa batter on top of cake batter.  Use a skewer to stir the batter to create a swirl effect pattern on cake.
10. Steam-bake cake in a preheated oven for 55 minutes.
11. Remove cake at once from tin and cool it on a wire rack.  Remove all paper linings when cooling cake to prevent vapour at the base and sides.

Notes from Happy Flour

"The recipe uses less flour which meant that the cake has a low gluten content to maintain it volume after it is baked. In other word the cake will shrink in height and width during cooling, so don't worry. This is a cotton soft moist cake".