1Preheat the oven to 180C/160C Fan/Gas 4. Lightly grease 3 x 20cm round cake tins with a little Stork, then line the bases with baking paper.
2Put all the cake ingredients into a large bowl then beat with an electric mixer until smooth and combined.
3Divide the mixture evenly between the tins. Bake for 23-27 mins or until golden on top and pulling away from the sides of the tins. Allow to cool in the tins for 10 mins, then turn out onto a wire rack to cool completely. Reduce the oven temperature to 90C/70C Fan/Gas ¼.
4For the meringue, whisk the egg white in a medium-sized bowl until it holds soft peaks. Sprinkle in the sugar, a little at a time, whisking all the while, then continue to whisk until stiff peaks form.
5Spoon the meringue mixture into a piping bag fitted with a plain round nozzle. Line a baking tray with baking paper and pipe the meringue into about 12 smallish ‘kisses’. Bake for 1 hr 40 mins to 2 hrs, or until dry and firm. Allow to cool fully, then crush half the kisses into small pieces.
6Whip the Elmlea with 1tsp of the vanilla paste until it holds stiff peaks.
7Reserve 100g of the raspberries and set aside. Divide the remaining raspberries and the strawberries into 3 equal quantities.
8Spread half the whipped Elmlea over the first cake layer, leaving a 2cm border around the edge. Top with one third of the berries and half the crushed meringues. Top with the second cake, then repeat with the remaining Elmlea and crushed meringues and another third of berries. Top with the final cake.
9For the buttercream, beat together the Stork, icing sugar and remaining vanilla paste until light and fluffy. Use a palette knife or scraper to spread the sides of the cake with a very thin layer – the texture and edges of the cake should be visible through it. Spread the remaining buttercream over the top of the cake, then chill for 20 mins.
10Melt the white chocolate in a glass bowl over a pan of simmering water. Stir until smooth, then set aside and allow to cool slightly but not solidify.
11Put the reserved raspberries into a bowl and mash with a fork, then transfer to a sieve and press through with the back of a spoon, discarding the seeds and any pulp. You should end up with about 50ml juice.
12For the glaze, pour the raspberry juice into the melted chocolate and mix together until smooth and a uniform pink colour. If the chocolate ‘seizes’ and gets thick or lumpy, zap in the microwave for a few seconds, then stir until smooth again.
13Pour the glaze over the top of the cake and gently spread it to the edge, teasing it over the sides so that it drips down.
14Top the cake with the remaining berries and the meringue kisses – crush a meringue to sprinkle over, if you like.
15To enjoy the cake at its best, serve on the day it is made, as the meringue will soften over time. It will, however, taste delicious for up to three days after baking.