Nutrition: per serving
Oil and line three 15cm loose-bottomed cake tins. Heat the oven to 200C/180C fan/gas 6. In a large bowl, whisk the olive oil, eggs and soured cream until combined. Add the coffee to 165ml of hot water and stir.
Slowly whisk the coffee into the oil mixture. In another large bowl, whisk the flour, cocoa, bicarb, baking powder, sugars and 1 tsp of salt, breaking up any lumps of sugar. Slowly drizzle the wet ingredients into the dry, whisking until smooth. Divide the batter between the three tins (about 380g in each) and bake for 20-25 mins or until a skewer inserted into the middles comes out clean. Leave to cool in the tins for 20 mins, then invert onto a wire rack to cool completely.
While the cakes cool, make the praline. Roast the hazelnuts on a baking tray at 200C/fan 180C/gas 6 for 10-12 mins or until lightly golden. Put 200g of the sugar in a small pan and melt over a low heat, coaxing the melted amber parts into the uncooked parts with a spatula until it forms an amber caramel. Quickly and carefully pour it over the warm nuts, using a spatula to make sure they’re all covered. Leave to cool for 20-30 mins or until hard. Once the praline has cooled, break it up, put it into a food processor and blitz to a fine powder.
Next, make the stewed pears. Put the pears, lemon zest and juice, sugar and ginger with 125ml of water in a medium pan. Cook over a medium heat for 30 mins, stirring regularly, until broken down and slightly caramelised. Set aside to cool and then chill. Fish out the ginger.
For the buttercream, put the egg whites and 300g of sugar in a heatproof bowl, and put over a pan of barely simmering water, making sure the water doesn’t touch the bottom of the bowl. Gently stir for 5-6 mins or until you can no longer feel any grains of sugar between your fingers. Transfer to the bowl of a stand mixer fitted with the whisk attachment. Whisk on a medium speed for 15 mins until the mixture becomes meringue-like and has reached stiff peaks. Add a fifth of the butter at a time, whisking to combine before the next addition. It may look curdled and soupy but be patient and keep whisking until you have a smooth, fluffy buttercream. Fold in the praline powder and chill for 30 mins Once chilled, put a third of it into a piping bag with a large round tip nozzle.
Slice off any domed tops from the cake with a serrated knife. Put the first cake layer down so the flattest side is on top. Pipe a 11⁄2cm-thick border of buttercream around the edge of the cake, filling the circle with slightly less buttercream and flattening it slightly in the centre to fit the pears. Put half of the pears in the centre of the buttercream and push them down slightly. Put the next sponge on top and repeat until you have a final layer on top. You can use skewers to dowel the cake for added stability, if you like.
Crumb coat the cake by spreading a thin layer of buttercream on the top and sides of the cake, then chill for
30 mins. Use the rest of the icing to create a thicker coating, using a small palette knife and a turntable to flick lovely swoopy edges. Decorate with edible flowers and enjoy. Will keep in the fridge for three days.
