Taro (Yam) Layered Cake

It's Mothers' day! I know my post is outdated; my aim was to get this post done before the month of May ends. Was thinking hard on what type of cake to bake for my mum... we are a typical Asian family where cream, butter, milk do not appear frequently on the dining table. Much as my parents' repertoire of dining options has expanded, possibly under duress, from 3 kids who have grown up and have a slightly wider scope of dining experiences; the selection of cakes had still been limited to fruit cakes.

With the subsequent appearance of 4 little nieces and nephews, woohoo! my parents kind of learned to accept chocolate-based cakes. Yet, it's difficult to satisfy 8 adults and 4 kids.. my brother and father never let me forget that green tea red bean cake I bought years agoooo! A recent pandan kaya cake from Bangawan Solo had the kids rejecting the pandan layers all together. Durian cakes are well-accepted though.. well, maybe I will try that one day but i always thought that durian should be enjoyed in it's purest, original, creamy form. *drool*

Anyhow, after much googling, I decided on a Yam Layered Cake. I remembered the taste of it from a random cake shop in a Taiwan MTR and it's been lingering on my mind for a long time. This is definitely NOT a preferred all-family cake; I'm sure it's not something everyone in my family will like but well, it's the mum's day and she loves taro! Taro cake it is going to be!

There is surprising a large number of recipes online and each looks great! I decided on using a sponge cake recipe from the Australian Sponge Cake Queen and the yam layer from Aunty Yochana.

It's not too difficult but time-consuming, it took me about half a day to do this since it involves steaming, mashing then cooking the yam, of which I'm really not too good at. The time spent was worth it though as my parents love the cake or so i think, judging by their request for a second serving each and they happily kept the rest of the cake for breakfast the next day. Disclaimer : Half the family kept their distance and the kids only pecked at the sweet mango slices, happily. Oh well, as long as my parents like it. Yay!

Recipe:

Sponge Cake
Flour mixture : Put 2 heaped tsp of plain flour + 1/2 teaspoon baking soda + 1 teaspoon cream of tartar into a 1-cup measuring cap and fill up the remainder of the space with cornflour.
4 eggs, room temp
120g fine-grained sugar
1 tsp vanilla essence

1. Preheat oven to 190C. Prepare 2 8-inch cake pans, no need to line the pan, just grease the sides. (I may line the bottom next time though)
2. Sift flour mixture 3 times.
3. Beat eggs and sugar on high speed for 7 minutes, add vanilla essence and combine.
4. Turn mixer to low speed and gently add flour mixture, beating for 1 minute until smooth.
5. Pour batter into the 2 cake pan, tap gently to remove air bubbles and bake for 20 minutes.
6. Remove from oven and leave to cool fully.

Note:
The sponge cake baked beautifully, however they are on the dry side.. I'm not sure why or maybe it needs a coating of sugar syrup?
I didn't have cream of tartar so I omitted it. No difference to the rising.

Yam Paste Layer:
500g yam, after being steamed and mashed (I cut into small cubes, steamed for 20 minutes until soft and mash them while hot)
80g sugar
300ml fresh milk (I used Meiji skimmed milk)
50 gram unsalted butter
50 gram coconut powder

1. Melt the butter and sugar in milk over low heat.
2. Stir in coconut powder and well-mixed.
3. Add the mashed yam and simmer over med heat until it forms a paste.
4. Leave to cool thoroughly.

Note:
My paste was very watery and I was worried it would not be able to form a layer so I cooked it over low heat for very long, almost an hour before it dries somewhat to form a paste. I would probably reduce the milk or increase the yam in the next attempt.

Stabilised Whipped Cream:
300ml heavy cream (I used Bulla Thickened Cream)
1/4 cup sifted icing sugar
1 tsp vanilla essence
1 tsp plain gelatin, cooked in a small pan over low heat with 4 tsp water to form a gel, keep the pan slightly submerged in hot water to prevent it from hardening.

1. Beat the cream  and sugar on high speed until it turns slightly creamy.
2. Add the gelatin gel, vanilla essence and continue beating at high speed until stiff.

Note:
Whip the cream only just before assembling the whole cake.
Before whipping, keep mixing bowl and beater in freeze to make them really cold. Cream must be whipped in cold condition in as short a time frame as possible to prevent curdling.
I added gelatin as whipped cream tends to melt really fast. Since our weather has been particularly hot recently, I wanted a stable whipped cream to ensure my mango slices would not slide. Indeed it worked perfectly and did not affect the taste at all.

Assembly:

1. Cut the cake into the number of layers needed. I cut one of the layers into 2 and kept 1 intact so I've 3 layers. This is to be able to fit 2 layers of yam paste into the cake.
2. Place the bottom layer on the cake tray that you will already be using to hold the cake.
3. Layer 1 layer of yam paste and place the 2nd sponge cake atop. This layer of yam paste need not be too thick as the top 2 layers will add weight and squeeze the yam out.
5. Layer the 2nd, thick coat of yam paste and place the 3rd sponge cake on top.
6. Spread the whipped cream on the top layer, followed by the sides. Try to smooth the frosting on the side, something I'm still a real novice at.
7. Arrange the mango slices into a rose shape on top. (I used 3 ripe, medium-sized mangos and sliced them vertically downwards, in thin slices)