Directions

1. Heat oven to 180C/160C fan/gas 4. Grease two 20cm cake tins (one should be at least 8cm deep) with oil, and line the base and sides with baking parchment. Tip the egg yolks, caster sugar and vanilla into a large bowl, and the egg whites into a second large bowl. Combine the flour, almonds and 1 /4 tsp salt in a third bowl.
2. Using an electric hand whisk, beat the egg whites until doubled in size and holding soft peaks. Transfer the beaters to the egg yolk bowl (no need to clean the beaters first) and whisk until the mixture is thick and pale. Lift the beaters and drizzle the mixture around the bowl - a ribbon should sit on the surface for 2-3 secs.
3. With a large metal spoon, transfer a spoonful of egg white to the yolks, and mix to loosen the consistency. Add the remaining whites and gently fold into the yolks, trying to retain as much volume as possible. Stop before the mixture is totally combined. Sprinkle the flour and almond mixture evenly over the surface, then drizzle the cooled butter around the edge of the bowl. Fold everything together until just combined, making sure you scoop the spoon right down to the bottom of the bowl to catch the butter and any pockets of flour. Divide the mixture between the cake tins, level the surfaces, then bake on the middle shelf of the oven for 22-25 mins. Test the cakes are done by inserting a skewer into the centre - it should come out clean. Cool in their tins on a wire rack for 30 mins, then remove the tins and parchment, and leave to cool completely.
4. Boil the kettle. Put the gelatine in a bowl of cold water and set aside to soften. Pour 150ml cream and 50ml hot water into a saucepan. Add the matcha powder and whisk over a gentle heat until well combined and steaming. Remove from the heat. Squeeze the water from the gelatine leaves and add them, one by one, to the hot matcha cream, whisking until they're dissolved. Pour the warm cream into a bowl and put in the fridge to cool to room temperature - don't leave it too long or the gelatine will set.
5. Line the deepest of your 20cm cake tins with a double layer of cling film, ensuring the sides are well covered. Put one of the sponges in the tin, flattest-side down. Pour the remaining 450ml cream into a bowl and add the icing sugar. Whip until the cream is holding soft peaks, then fold through the cooled matcha cream. Scrape the cream into the cake tin and level the surface. Put the remaining sponge on top, flattest-side facing up, pushing the sponge gently into the cream. Wrap the tin in cling film and chill for at least 4 hrs.
6. Put the cream, chocolate and matcha powder in a saucepan and heat very gently, stirring until the chocolate has melted and the matcha is well mixed in. Set aside to cool and thicken for 10 mins. Remove the cake from the fridge and unwrap the tin. Invert the cake onto a cake stand or plate and remove from the tin and the cling film. Using a palette knife held at a 90-degree angle to the side of the cake, scrape around the edge to remove any excess mousse and give the cake a smooth finish. Using baking parchment, create a tight collar, sitting about 2cm taller than the cake. Pour the cooled chocolate glaze over the top, smoothing it to the edge - the collar should prevent it from dribbling down the sides. Chill for 30 mins more, or for up to 24 hrs.
7. Carefully pull off the parchment collar. Hold a chopping board (or another object with a straight edge) over half the cake and dust the exposed surface with icing sugar. Arrange fresh cherries and cherry blossom or another edible flower on top, if you like, and serve immediately.