Knickerbocker Glory Gâteau

With its soft vanilla filling, fruity touches and swirl of whipped cream, this showstopper has all the fun of the beloved retro sundae in cake form.

If you want to take a shortcut, you can use 175g drained tinned peach slices in syrup (reserve the syrup) and 100g shop-bought raspberry coulis.

Hands-on time 1hr, plus cooling. Cooking time about 1hr. Serves 18

FOR THE CAKES

 400g unsalted butter, softened, plus extra to grease

 400g caster sugar

 6 medium eggs, beaten  350g self-raising flour

 2tsp vanilla extract

 100g ground almonds  2tbsp whole milk

 250g raspberries FOR THE FILLING AND TOPPING  75g cornflour  100g caster sugar  350ml whole milk  3 medium egg yolks  1tbsp vanilla bean paste  50g unsalted butter, cut into cubes  500ml double cream  15g icing sugar, sifted FOR THE POACHED PEACHES AND RASPBERRY SAUCE  2 peaches, halved and destoned  75g caster sugar

 100g raspberries FOR THE DECORATION, OPTIONAL

 Cocktail cherries, drained  Fan wafers

1 Preheat oven to 170°C (150°C fan) mark 3. Grease and line the base and sides of 2 x 20.5cm round, deep cake tins. For the cakes, using a freestanding mixer or a handheld electric whisk and a large bowl, beat the butter and sugar until light and fluffy, about 5min.

2 Gradually beat in the eggs, adding a spoonful of the flour if the mixture looks as if it might curdle. Beat in the vanilla. Using a large metal spoon, fold in the (remaining) flour and the ground almonds, followed by the milk and 200g of the raspberries.

3 Divide the mixture equally between the prepared tins and spread to level. Dot over the remaining 50g raspberries and bake for 50min-1hr, or until a skewer inserted into the centre of the cakes comes out clean. Leave to cool

in the tins for 10min, then transfer to a wire rack to cool completely.

4 Meanwhile, make the custard filling. In a medium pan, stir the cornflour and sugar. Gradually whisk in the milk, until smooth. Next, whisk in the egg yolks and vanilla bean paste.

5 Cook over medium heat, whisking constantly, until very thick (the mixture will need to boil). Remove from the heat. Working quickly, whisk in the butter, a few pieces at a time (it may look like it won’t mix in initially, but keep whisking). Scrape into a large heatproof bowl, lay baking parchment or clingfilm directly on the surface to stop a skin forming and leave to cool completely.

6 Make the poached peaches. Cut each peach ½ into 6 wedges. Heat the sugar and 75ml water in a medium pan over low heat, stirring until the sugar dissolves. Turn up the heat and bring to a simmer. Gently stir in the peach slices and remove the pan from the heat. Set aside for 5min, until the peaches are just tender. Carefully strain into a jug, reserving the syrup. Set the peaches aside.

7 Make the raspberry sauce.

Put 2tbsp of the reserved syrup (keep the rest) into a food processor with the raspberries and whizz until smooth. Push through a fine sieve into a jug, working the mixture well (discard the seeds).

8 To assemble the cake, beat the custard filling with a handheld electric whisk to loosen. Gradually whisk in 275ml of the double cream to make a smooth, spreadable filling. In a separate bowl, whisk the remaining 225ml double cream with the icing sugar until the cream just holds its shape.

9 Halve the sponges horizontally. Arrange a sponge bottom on a cake stand or serving plate and brush the cut-side with some of the reserved syrup. Spread over ⅓ of the custard filling, then dot over ⅓ of the peach slices and drizzle over ⅓ of the raspberry sauce. Repeat layering twice more. Brush the cut-side of the remaining sponge with the syrup, then sit it on the cake tower, cut-side down. Loosely spread on the cream topping. Decorate with cocktail cherries and fan wafers, if using. Serve in slices. PER SERVING 642cals, 8g protein, 43g fat (24g saturates), 56g carbs (37g total sugars), 2g fibre GET AHEAD Prepare to end of step 7 up to a day ahead. Leave the cakes to cool completely in the tins, then wrap in foil and store at room temperature. Transfer the cooled custard, peaches in syrup and raspberry sauce to separate sealed containers and chill. To serve, remove from the fridge 30min before assembling the cake.

TO STORE Once assembled, the cake is best served on the day, but leftovers will keep in an airtight container in the fridge for up to 2 days.