For the natural yogurt sorbet
185ml cold water
175g caster sugar
50ml freshly squeezed lemon juice
400ml full-fat natural yogurt
For the candied oats
100g jumbo rolled oats
50g pumpkin seeds
1tbs clear honey
1tsp amaretto liqueur
For the peach sauce
250g fresh (stoned) peaches, roughly diced
100g caster sugar
100ml cold water
For the peach upside-down cakes
250g unsalted butter, softened
250g dark muscovado sugar
6 fresh peaches, firm but ripe
2 large free-range eggs
100g plain flour
100g ground almonds
1tsp baking powder
Finely grated zest of 1 lemon
A pinch of table salt
First, prepare the sorbet. Put the water and sugar in a small saucepan and cook over a medium heat, stirring to dissolve the sugar. Once the sugar has dissolved, bring the mixture to a simmer and simmer for two minutes. Remove from the heat, pour the syrup into a mixing bowl and leave to cool for 15 minutes, then add the lemon juice and yogurt and mix well. Cover and chill for one hour.
Pour the chilled mixture into an ice-cream maker and churn until frozen (following the manufacturer's instructions for your particular model). Keep frozen until you are ready to serve (then keep any leftover sorbet in the freezer and use within one week).
Next, prepare the candied oats. Preheat the oven to 180°C/gas mark 4. Line a baking tray with non-stick baking paper and set aside. In a mixing bowl, mix together the oats, pumpkin seeds, honey and liqueur, then spread the mixture out evenly on the prepared baking tray. Bake in the oven for five to eight minutes or until the oats and pumpkin seeds are toasted and golden brown. Remove from the oven and leave the mixture to cool completely on the baking tray.
Once cool, break the candied oats into smaller pieces, then transfer to an airtight container until you are ready to serve. The candied oats can be made in advance and will keep in an airtight container in a cool, dry cupboard for up to one week.
Meanwhile, make the peach sauce. Place the peaches, sugar and water in a saucepan and cook over a medium heat, stirring to dissolve the sugar. Once the sugar has dissolved, bring the mixture to a simmer and simmer for about five minutes or until the peaches are soft. Remove from the heat, carefully transfer the mixture to a blender and blend until smooth, then pour the peach sauce into a bowl and chill it rapidly over ice. Once cold, cover and refrigerate until you are ready to serve.
Prepare the peach upside-down cakes. Preheat the oven to 180°C/gas mark 4. Grease 12 8cm x 3.5cm individual round cake tins, then line the bases with non-stick baking paper and set aside. Put 125g of the butter and 125g of the sugar in a bowl and cream together until pale and fluffy. Divide the mixture between the prepared cake tins, spreading it evenly to cover the bases completely. Set aside at room temperature while you prepare the peaches.
Score a cross in the base of each peach using a sharp knife. Blanch the peaches in a pan of boiling water for 30 seconds, then remove using a slotted spoon and plunge them into a bowl of iced water. Drain the peaches, then peel them (the skins should slide off easily now). Cut the peaches in half and remove the stones. Put a peach half, cut-side down, into each prepared cake tin, on top of the creamed mixture. Set aside while you prepare the cake batter.
Sift flour and baking powder. Put the remaining 125g butter and 125g sugar in a bowl and cream together until pale and fluffy. Add the eggs, one at a time, beating well after each addition. Add the flour, ground almonds, baking powder, lemon zest and salt, then lightly fold the dry ingredients into the creamed mixture until combined, but do not over-mix. Divide the batter between the prepared tins, carefully spreading it evenly over the peach halves.
Bake the cakes in the oven for about 20 minutes or until well risen and cooked. Remove from the oven and then immediately and carefully invert the cakes on to a heatproof board or tray (so that the peach halves are facing uppermost) and remove the tins (if you do not turn them out immediately, they will stick to the tins). Remember to take extra care as hot caramel can cause serious burns. Serve the upside-down cakes warm.
To serve, spoon a tablespoon of the peach sauce on to each serving plate and place a warm peach upside-down cake on top of the sauce. Place a teaspoonful of the candied oats on top of each peach half and then place a scoop of the yogurt sorbet on top. Serve immediately.