Rachel Allen was brought up in Dublin and left home at eighteen to study at the world-famous Ballymaloe Cookery School. Rachel is now a busy ...
375g (13oz) plain flour
4 tsp baking powder
1 tsp salt
225g (8oz) butter, softened, plus extra for greasing
675g (1 1/2lb) caster sugar
325ml (11 1/2 fl oz) milk
2 tsp vanilla extract
9 egg whites (about 250ml/9fl oz)
For the Praline
100g (3 1/2oz) caster sugar
100g (3 1/2oz) hazelnuts (skin still on)
For the Custard Cream
25g (1oz) caster sugar
3 egg yolks
175ml (6fl oz) milk
15g (1/2oz) cornflour
1 tsp vanilla extract
100ml (31/2fl oz) double or regular cream
For the Frosting
4 large egg whites
250g (9oz) caster sugar
Pinch of salt
Preheat the oven to 180°C (350°F), Gas mark 4, then butter the sides of the cake tins and line the bases with a disc of baking parchment. First make the sponge. Sift the flour, baking powder and salt into a bowl. Cream the butter until soft in a large bowl or in an electric food mixer. Add 450g (1lb) of the sugar and beat until the mixture is light and fluffy. Add about a third of the sifted flour along with about a third of the milk and continue to mix gently, in thirds, until all of the flour and milk is well mixed in, then stir in the vanilla extract.
In the bowl of an electric mixer, whisk together the egg whites until foamy, then add the remaining sugar and whisk until the meringue holds stiff glossy peaks. Mix in a quarter of the meringue to the cake mixture, then carefully fold in the rest until fully incorporated. Tip the mixture into the prepared cake tins and bake for 30 minutes or until a skewer inserted into the centre of each cake comes out clean.
Remove from the oven and allow to cool for 10 minutes, then loosen the sides of each tin with a small, sharp knife and carefully remove the cakes from the tins before placing on a wire rack to cool completely. (The sponge can be made up to a day in advance and kept in an airtight container.)
To make the praline, first line a baking tray with baking parchment and set aside. Place the sugar in a frying pan and scatter the hazelnuts over the sugar. Place the pan over a medium heat to allow the sugar to caramelise, swirling the pan every so often to ensure it caramelises evenly. Cook until the sugar has completely melted and is a deep golden colour and the hazelnuts are coated evenly. Transfer the coated nuts to the prepared baking tray.
Before the caramel has a chance to harden, set apart about 10 hazelnut clusters (with 4–5 hazelnuts in each cluster) for decorating. Using two forks, spread apart the remaining hazelnuts and leave the praline to cool completely. Once cool break up the praline using your hands, then place the pieces (but not the reserved clusters) in a food processor and whiz until it resembles slightly coarse breadcrumbs.
To make the custard cream, place the sugar in a saucepan with the egg yolks, milk, cornflour and vanilla extract and whisking all the time bring just to the boil, then reduce the heat to low. Then cook, continuing to whisk, until thickened. Immediately remove from the heat before transferring to a bowl to cool completely. In a separate bowl, whip the cream just until it holds stiff peaks. Add the praline to the cooled custard and mix in, then carefully fold in the whipped cream. Cover the praline custard cream and place in the fridge until you are ready to use it.
You can now assemble the cake.
Place one of the cakes on a cake stand or plate. Spread with half of the praline custard, then cover with a second cake. Spread the other half of the custard cream over the cake, then top with the third cake. Use a pastry brush to brush off any excess crumbs from the cake.
Next make the frosting. First place a palette knife in a jug or bowl and put the kettle on. It makes it really easy to frost this cake if you can use a palette knife that has been dipped in hot water. Place all the frosting ingredients in a heatproof bowl, add 2 tablespoons of cold water and set over a saucepan of simmering water. (The bowl should sit snugly over the pan, with its base high enough above the water that it does not come into contact with it.) Whisk slowly by hand until the sugar has completely dissolved and the mixture is foamy.
Continue to heat and whisk until the mixture reaches 60°C (140°F) when measured with a sugar thermometer – this will take about 4 minutes. If you don’t have a thermometer, you can gauge whether the mixture is ready by how it feels and looks: it should be hot to the touch, glossy white in appearance and starting to thicken.
Quickly remove the bowl from the pan and pour the mixture into the bowl of an electric food mixer fitted with the whisk attachment. Alternatively, whisk in the original bowl using a hand-held electric beater. Whisk on a high speed for about 3–5 minutes or until the frosting is very thick, glossy and has cooled. Pour boiling water into the jug or bowl holding the palette knife.
Before the frosting has a chance to cool and therefore set, spread it with the hot, wet palette knife over the top and all around the sides of the cake, covering it as evenly as possible. You can go for a smooth appearance or a slightly peaked look by tapping the flat side of the palette knife over the frosting. As you pull it up, it should create little peaks. Do this all over the cake.
Decorate around the top edge of the iced cake with the reserved hazelnut praline clusters.