Preheat the oven to 180 C / Gas 4. Grease a 23cm cake tin.
In a saucepan, combine the butter and brown sugar and stir over a medium heat until melted. Pour into the base of the prepared cake tin. Arrange the sliced peach and plum segments together with half of the raspberries in a pleasing pattern in the base of the tin.
Place the egg whites into mixing bowl and whisk with a handheld mixer until stiff peaks form. Gradually whisk in half of the caster sugar until thick and glossy.
In a separate bowl, whisk the egg yolks and the remaining caster sugar together until pale, thick and creamy then gently fold in the ground almonds and add the vanilla extract and lemon juice. Gradually fold in the egg whites, taking care to preserve as much air as possible. Carefully pour the cake mixture over the fruit, ensuring that you do not move the fruit arrangement. Smooth the top with a spatula.
Bake in the preheated oven for 50 to 60 minutes, or until a skewer inserted into the centre comes out clean. Remove from the oven and allow to cool for 10 minutes in the tin.
Once cooled, place a serving plate over the top of the cake then flip smoothly upside down. Allow the cake tin to rest for a few moments upside down over the plate, it should slip out all by itself. Remove the cake tin. Allow to cool then top with some fresh raspberries and serve with some extra thick double cream.