Blackberry mousse gateau

Instructions

1. Preheat the oven to 180°C, fan 160°C, gas mark 4. Mist a 20cm springform cake tin with cooking spray and line with baking paper.
2. In a bowl, beat the eggs and caster sugar together until pale, thick and voluminous – this will take 6-8 minutes.
3. Sift the flour and cinnamon into the bowl, add the vanilla and fold together. Spoon into the prepared tin, level the top, and bake for 25 minutes until risen.
4. Let cool in the tin for 10 minutes, then release the cake and transfer to a cooling rack to cool completely. Wipe the tin clean using kitchen paper, then mist the side with cooking spray and line it with baking paper.
5. While the cake is cooling, make the mousse. Soak the gelatine in cold water for 5 minutes until softened. Put the blackberries in a small pan with the caster sugar and cook over a mediumlow heat until the sugar has dissolved and the berries start to break down. Bring to a boil and cook for 1 minute until syrupy. Remove from the heat and transfer to a large heatproof bowl.
6. Squeeze the excess water from the gelatine, drop the leaves into the hot blackberry mixture and stir until dissolved. Set aside to cool for 15 minutes, then gently stir in the yogurt.
7. In a separate bowl, whisk the egg white to soft peaks, then fold into the cooled yogurt mixture. Set aside.
8. When the cake has cooled, halve horizontally, using a large serrated knife. Press the bottom half into the prepared tin, then spoon over the mousse. Top with the remaining sponge, gently press down, and chill for at least 8 hours.
9. To serve, release the cake from the tin and transfer to a cake stand. Decorate with the blackberries and icing sugar.