The challenge from Klub Berani Baking was to make Lapis Legit Prune. Since I am not fan of sweet dried fruit (well, love the sour ones thou...), so I simply omit the prune from the recipe and added Lapis Legit powder instead. I also replace the margarine on the recipe with butter. The original recipe the KBB sent to me has 200 grams butter and 200 grams margarine. I baked my Lapis Legit using 400 grams butter instead. All butter and no transfat!!
There are several things I learned from the process, which is that the batter is in fact an emulsion... mostly contains fat from the butter and eggyolk. The butter should be a little bit cold, and cut in cubes. When whisking, either the egg yolks or the butter, make sure that the egg yolk or the butter turn really pale, which means we manage to incorporate a lot of air in it. This is an important step to have a very soft consistency that will make the mixing way much easier.
As the batter contains a lot of fat from the butter, it is important to keep the batter away from any heat. As a guidance, the room temperature to keep is where butter is not melted but not becomes solid too... so, about 20-25 ºC would be perfect (the refrigerator would be too cold, and you don't want to open your fridge's door too often). If the temperature is too hot, the batter will melt and separate. Remember that the process of making layers could take several hours. Usually, when the oven in the kitchen is on, the kitchen temperature would be hotter, risking to melt the batter. So what I did was, I put the bowl of the batter in an air-conditioned room (my dining/living room) and just took about 1/2 - 1 Cup at a time, enough for 2 - 4 layers. The rest stayed in a cooler room. Well, for you who live in a cool climate country, you don't need to do this precaution, but for us living in a hot tropical place... I think that was the best we can do.
I think I have to make another one. The layers on my cake were not even in color. Some are a bit darker and some are lighter. Even on the same layers! I see that it's because I put the baking pan too close to the top heat. I should have lowered the rack make it a bit further away from the heat. Like that it will have more even color on each layer. As we know, each oven is different, so we have to make experiment to find the perfect condition.
So, this is my recipe, after I adjusted the recipe that I got from the Klub Berani Baking...
400 gram butter, cold from the fridge, cut in small cubes
2 tbsp condensed milk
2 white eggs
200 gram caster sugar
1 tsp vanilla extract
20 gram cake emulsifier (TBM)
60 gram cake flour
25 gram of cornstarch
2 tbsp Lapis Legit powder
Line the bottom of a 18 cm x 18 cm x 5 cm baking pan with parchment paper. Put aside.
Sieve together the flour, cornstarch and Lapis Legit powder. Set aside.
Preheat the oven to 180 ºC.
In a big bowl, on a stand electric mixer, whisk the eggyolks, white eggs, caster sugar, emulsifier and vanilla extract until it's pale in color and double in volume (about 20 minutes).
In a smaller bowl, whisk the butter and the condensed milk, until it's light and pale in color (about 12-15 minutes).
While the mixer running, add the whisked butter mix to the egg sugar mix, two table spoonfull at a time. We are going to make emulsion here, so be patient adding the butter. One spoonfull at a time... until all the butter has been well mixed in. The batter will deflat a little bit, but that's OK.
Stop the electric mixer, and using a spatulla, add the flour mix into the batter. Fold it in to mix well.
Use 1/4-cup measuring cup to measure the batter for the layers.
Start the first layer a little bit more than 1/4 cup. Smooth the surface with a spoon or spatula. Bake for 5 minutes or until the surface is brown, and take the pan out from the oven. Add another 1/4 cup of batter on top of the first layer. Put it back in the oven for another 5 minutes or until the surface is brown. Then take it out from the oven to add another layer.
After the third layer, switch to the top heat. Adjust the flame smaller so not to burn the cake. We only need it to brown the layers' surface. It's about 3 minutes for each layer. Be carefull not to burn a layer.
In the mean time, keep the rest of the batter from heat.
Do the same layering process with the top heat until all the batter is used up. Every time when you see the surface is "bubbled", flatten it by pressing it down with a spoon.
After all the batter is used up, switch again to the bottom heat, set to 180 ºC. Bake for another 15 minutes.
Let it cool before removing the cake from the pan.
Slice a thin layer on each side to make it neat and reveal the layers.
Cut one piece for yourself and enjoy.