Method

• 1.
  Preheat oven to 160°C. Grease and line the base and sides of 2 x 20cm cake pans with baking paper.

• 2.
  Beat the butter and sugar in a stand mixer fitted with the paddle attachment until thick and pale.
• 3.
  Add the eggs, one at a time, beating well after each addition. Fold through sour cream, flours and vanilla.
• 4.
  Divide between pans and bake for 55 minutes or until a skewer inserted in the centre comes out clean. Cool in pans. Using a serrated knife, trim the tops of the cakes to level, then halve the cakes horizontally. Enclose in plastic wrap and set aside until needed.
• 5.
  For the peach filling, place the peach, sugar, vanilla and butter in a large, deep frypan over medium heat. Cook, stirring frequently, for 20 minutes or until very tender.
• 6.
  Stir in the flour and cook for 2-3 minutes until thickened. Meanwhile, soak gelatine in a bowl of cold water for 5 minutes to soften. Squeeze excess water from gelatine, then stir into peach mixture until melted and combined.
• 7.
  Remove from heat and cool completely. When cool, transfer to a food processor and whiz until smooth. Fold through the mascarpone until smooth.
• 8.
  To assemble, place one layer of cake on a cake stand or serving plate. Top with one-third peach filling, then press one-third raspberries into filling. Repeat layering twice more, finishing with a final layer of cake. Chill until needed.
• 9.
  For icing, beat butter and icing sugar in a stand mixer fitted with the paddle attachment until pale.
• 10.
  Add cream cheese and beat until smooth. Using a palette knife, spread a thin layer of icing over the cake to seal in any crumbs, then chill for 20 minutes to firm up.
• 11.
  Divide remaining icing between 2 bowls, with 1 portion slightly larger than the other. Fold food colouring, if using, through the smaller portion.
• 12.
  Spread coloured icing around base of cake, then spread remaining icing over the top and halfway down the sides. (If not using food colouring, ice entire cake with white icing.)
• 13.
  Scatter freeze-dried raspberries over the cake to serve.