Matcha Cake with Azuki Bean Buttercream 抹茶红豆奶油蛋糕

Cake base:
egg yolks 4(A)
sugar 30g
oil 30g
milk 50g
cake flour 45g
corn flour 15g (or corn flour 24g + plain flour 36g)
matcha powder 10g

egg whites 4(A)
sugar 40g

180c - 16 mins using cake roll mould, cut into 2 equal pieces of cakes.

Reduced sugar swiss meringue buttercream:
egg whites 2(A)~74g
sugar 52g
salt 1/16tsp
unsalted butter 134g(cool but softened, cut into tablespoon-sized cubes)
vanilla bean paste 1tbs
lemon juice 2tsp(add to counter the sweetness)

1. Place white eggs, sugar & salt in a heatproof mixing bowl. Heat about 1" worth of water in a deep saucepan whereby the mixing bowl is able to sit comfortably over without the base touching the water. Use a hand whisk to whisk the egg whites & sugar over simmering water until all sugar is dissolved & the foamy egg whites are 71.1C.
2. Remove from heat immediately& use an electric mixer to beat on high speed until cool, firm & glossy. About 10 minutes.
3. Reduce mixer speed and add butter one cube at a time & continue beating. Just keep beating even it starts to curdle, and gradually adding butter and it will all come together in the end.
4. Beat on high speed again for a couple of minutes until pale and fluffy. Add vanilla & lemon juice & beat until well incorporated.
5. Unused buttercream may be frozen. Simply defrost at room temperature & rewhip before using.
6. This recipe will come out with 260g smbc, use 160g for azuki bean smbc, another 100g for topping.

Azuki Bean swiss meringue buttercream:
reduced sugar smbc 160g
mashed canned azuki bean 100g(must well-drained)
salt 1/8tsp

1. If using frozen-thawed smbc, rewhip the cream before adding in mashed azuki bean & salt. Whip everything together with electric mixer until light and fluffy.

Azuki Bean jelly:
azuki bean puree 120g(mashed azuki bean sieved through)
water 120g
sugar 20g
salt 1/8tsp
instant agar powder 2tsp(if using non-instant is 1.5tsp)

1. Combine everything into a small saucepan & bring to boil while stirring continuously. Boil for a minute while stirring to ensure agar powder is fully dissolved as we are making a firm jelly.
2. Pour into mould & chill in the fridge until firm. May prepare a day before assembly.