Rhubarb Custard Tea Cake - Rhubarb #3

I baked this cake twice. the first time, my custard sank and batter rose to the  top, creating a very funny looking cake that sunk.

The second time, I chilled the custard filling as a whole piece so that I can apply equal pressure to the base batter. The result was way better.

My source, Eat Little Bird has another recipe that didn't use custard powder. I used the custard powder versionbecause I just wanted to clear up my pantry. And she made the topping in another way so that she can sneak in more rhubarb. I totally agree with her on this, that this cake has too little rhubarb. But sometimes, we do choose looks over anything else, LOL.

Rhubarb Custard Tea Cake
Source: Eat Little Bird

Batter
200g butter
110g caster sugar
2 eggs
185gm plain flour
2 tsp baking powder
40gm custard powder

Custard Filling
25gm custard powder
50gm sugar
250ml milk
1 vanilla bean, scraped or 2 tsp vanilla extract (1 tsp if using imitation)
20gm butter

Topping
1-2 stalks of rhubarb
20gm butter, melted
2 Tbsp sugar

1. Prepare custard. Do this step ahead Place a piece of cling film in the 8 inch pan that you will be baking in. Rub vanilla seeds with sugar. Mix custard powder, vanilla sugar and milk together in a small saucepan. On medium low heat, cook it until it begins to thicken. Turn off the heat (it should still thicken), then add in butter and vanilla extract (if using instead of vanilla bean). Pour this custard into the film lined pan and fold the top down carefully. Let it cool down in the fridge for few hours, it will solidify.(Or if you are in rush for time, you can spread this filling onto the batter later)
2. Sift flour, baking powder and custard powder together.
3. Prepare batter. Cream butter and sugar together, then add in eggs one by one, beating well between additions. Put flour in and mix until a thick batter forms.
4. Preheat oven at 180C, fan OFF. Remove chilled custard from fridge. and lift the custard up with the cling wrap. Line the pan's side and base with baking paper.
5. Put half the batter into the pan and level it. Peel the cling wrap from the top of the custard and flip it onto the batter (smooth it, if needed). Top with the balance of batter. Smooth the surface.
6. Cut rhubarb into 3 inch long pieces, and try to fit as many as you can, from 10-12pcs if you can. Sprinkle with sugar and melted butter.
7. Bake in oven for 1.5 hours
8. Let it cool down completely before slicing.