Method

• 1.
  To make the ganache, place chocolate and cream into a large heatproof bowl. Set the bowl over a pan of simmering water and melt together, stirring occasionally. Once melted, remove from the heat and leave to cool. Stir the yoghurt into the cooled chocolate mixture. Cover and leave to set in the fridge for 8 hours or overnight.
• 2.
  Preheat oven to 160°C (fan-forced). Grease and line the base and sides of two 20cm round cake tins. Place butter and chocolate into a heatproof bowl. Set the bowl over a pan of simmering water and melt together, stirring occasionally. Once melted, remove from the heat and set aside. Sift together the flour, baking powder and cocoa powder into a bowl. Whisk in the caster sugar to combine.
• 3.
  Place eggs, water and yoghurt into the bowl of a stand mixer fitted with a whisk attachment and whisk until combined and there are no lumps (you do not need to aerate this mixture). Turn mixer to low speed, pour in the melted chocolate and whisk until combined. Scrape down sides of the bowl and swap to the paddle attachment. Add the dry ingredients and mix on low speed until just combined.
• 4.
  Divide the mixture evenly between the two prepared tins and bake for 1 hour 30 minutes, or until a skewer inserted in the centre comes out clean. Leave to cool completely in the tin. Meanwhile, while the cake is baking, prepare the quinces. Wash quince and remove any furry layer. Squeeze half a lemon into a large bowl of cold water. Peel and cut each quince into eighths, then remove cores and reserve both peel and cores. Place the quince in lemon water (this is to stop the quince oxidising too quickly).
• 5.
  Place peel and cores into a large saucepan with sugar and water and bring to a simmer over medium heat. Reduce heat to low and cook for 1-2 hours until the syrup has turned a rich red.
• 6.
  Remove cores and peel from saucepan and add quinces and the other half of the lemon. Cook on low and simmer for a further 1½ hours or until the quince is tender and has turned a pink-red. (The colour can vary depending on the quince and season.) Turn off the heat and leave to cool in the syrup.
• 7.
  Place ganache into the bowl of a stand mixer fitted with the whisk attachment and whisk for 2 minutes until light and airy. Refrigerate for 1 hour to firm.
• 8.
  Remove the cakes from the tin and trim the top of the cakes to make a flat surface. Carefully slice each cake into three layers horizontally.
• 9.
  When ready to assemble the cake, spread ganache over the cut surface of the cake rounds and stack, pressing each layer down slightly. (If the ganache is too soft, refrigerate after layering). Top with the final cake round and use the remaining ganache to ice the cake. To serve, top with poached quince, syrup and edible flowers.