strawberry yoghurt mousse layer cake

The main reason for baking this cake was to make genoise. I also wanted to make something light and fruity after the chocolate cake last week. Hence, the strawberry mousse layer cake which seems so very apt for the summer.

According to Wikipedia, a génoise cake (Genoese cake or Genovese cake) is an Italian sponge cake named after the city of Genoa and closely associated with Italian and French cuisine that does not use any chemical leavening, instead using air suspended in the batter during mixing to give volume to the cake. Hence, the beating of the eggs is the most important step to ensure that the cake turns out light and fluffy.

Rose gave an excellent recipe of classic genoise in The Cake Bible with detailed instructions. The only advice I can give is FOLLOW the instructions! My genoise failed the first time because I stopped beating the eggs after 3 minutes as the batter did not seem to be rising any more. That ended up with a genoise achieving half the intended height. For the second time, I beat the eggs at high speed for a full 5 minutes as intended and tweaked the recipe slightly to make it more moist. Thankfully it turned out perfectly soft, spongy and moist with a tender crumb (even without the sugar syrup). It is best eaten immediately or once cooled. If not, the frosting will help keep the cake moist and soft.

Strawberry yogurt mousse layer cake

Start by making the genoise (adapted from Rose's The Cake Bible)

2 oz unsalted butter
4 large eggs / 5 small eggs (~200g without shells)
100g caster sugar

50g cake flour

50g corn starch
2 tbsp warm milk
1 tsp vanilla essence

Preheat oven to 350F/175C (non fan)
Start boiling a pot of water in large saucepan.
Grease & flour a 9-inch springform pan.

Clarify butter by melting it in heavy saucepan over medium heat, partially covered to prevent splattering. Cook uncovered when butter looks clear till solids drop and begin to brown. Pour immediately through a fine strainer into medium sized bowl. This forms the beurre noisette which smells wonderfully delicious.
Add vanilla and milk to beurre noisette and keep warm.

Whisk eggs and sugar in large mixing bowl set over pan of simmering water, beat till eggs are lukewarm. Continue whisking at high(est) speed in stand mixer for full 5 minutes. The batter looks like whipped cream at the end of 5 minutes and looks like it's threatening to overflow.

While eggs are beating, sift together the flour and cornstarch.

Remove 1 scant cup of egg mixture and thoroughly whisk it into the beurre noisette.

Sift 1/2 the flour mixture into the remaining egg mixture and fold it gently but rapidly with a large balloon whisk. Repeat with remaining flour mixture until the flour has disappeared completely. Fold in the butter mixture until just incorporated.

Pour immediately into prepared pan and bake in oven for 25-35minutes till cake is golden brown and starts to shrink slightly from sides of pan. Unmold the cake immediately once it's out of the oven and cool on rack with cake right-side-up.

Next, prepare the strawberry yoghurt mousse cloud

140g strawberry yoghurt (Meiji brand)
3 tbsp caster sugar (to taste)
300g fresh strawberries, washed and chopped
450g fresh cream
2 tsp vanilla essence
2.5 tsp gelatine + 3tbsp water

Blend strawberries and yoghurt in electric blender till smooth. This makes about 240g of pureed strawberry yoghurt mixture.Add in sugar to taste.

Soak gelatine in water for 5 minutes, heat & stir to dissolve.
Add gelatine mixture to strawberry mixture. Mix well and strain if neccesary.

Whip fresh cream and vanilla essence to stiff peak.

Fold whipped cream into strawberry mixture in thirds.

Finally, assemble the cake

Torte genoise into half horizontally.

Place 1 layer of sponge into springform cake pan. (Sprinke sugar syrup on genoise if desired)

Pour half of mousse in and smooth it out.
Repeat with the next layer of sponge and mousse.

Cover with cling-wrap and leave in freezer for at least 2 hours

Unmold the cake by warming the sides of the pan with a hairdryer or warm towel.
Sprinkle white and dark chocolate shavings on top of the cake.

Serve.