Apple caramel layer cake

Method

1. Preheat the oven to 170ºC/fan 150ºC/gas 3½. Grease and line the sides and bottoms of 3 x 20cm cake tins with baking paper. For the sponge, peel, core and chop the apples. Put in a pan over a medium-high heat and add 100ml water and the 50g caster sugar. Cook for 10-15 minutes, stirring frequently and adding more water if necessary, until mostly turned to a purée. Take off the heat and leave to cool completely.
2. In a mixing bowl, cream the butter and sugar with an electric hand mixer until light and fluffy. Beat in the eggs one at a time, beating well after each addition. Beat in the cooled apple.
3. Sift over the flour and baking powder with a pinch of salt, then fold in with a metal spoon. Divide the mix equally among the 3 cake tins, then bake for 30 minutes until the sponge bounces back when touched. If you’re cooking all 3 cakes in the same oven you might need to take the top cake out and move the bottom one up to the top for an extra 5 minutes, leaving the middle one where it is.
4. Leave the sponges to cool for 10 minutes in the tins, then carefully turn out onto a rack to cool completely.
5. Meanwhile, make the filling. Peel and core the apples, then slice thinly lengthways. Put a pan over a medium-high temperature and add the sliced apples, sugar and butter.
6. Cook, stirring often, until the apples caramelise lightly (this should take about 15 minutes – lower the heat or remove the pan if it happens too quickly). When the apples are golden and caramelised, remove them from the pan with a slotted spoon, then put onto baking paper to cool.
7. When the cakes have cooled, put one sponge on a serving plate and top with half the Greek yogurt. Scatter over just under half of the sticky apples, then put a second sponge on top and repeat the process, saving some apples for the final decoration. Top with the remaining sponge.
8. Put all the caramel ingredients into a pan and heat gently to melt. Simmer for 7-8 minutes, stirring, until it turns into golden caramel.
9. Pour over the top of the cake, allowing the caramel to run down the sides. Leave the cake somewhere cool for 1 hour or so (see tip), then serve, cutting with a serrated knife.