Penny sweet parfait

Method

1. Line a 1 litre loaf tin with a double layer of cling film, leaving an overhang of a few centimetres. In a large, spotlessly clean bowl, whisk the egg whites with an electric hand mixer until they form stiff peaks when the mixer is removed. Whisk in the sugar a tablespoon at a time, whisking well after each spoonful. After you’ve added two thirds of the sugar, you can add it in large quantities. When the mixture forms a stiff, glossy meringue, stop whisking.
2. In a separate bowl, whip the cream with the lemon zest and vanilla seeds until it forms soft, pillowy peaks, then gently fold the cream into the whisked egg whites with a balloon whisk, folding in 1 tbsp first to loosen, then folding in a third at a time.
3. Very gently fold the halved sweets through the mixture, then transfer to the lined tin and put straight in the freezer for 7-8 hours.
4. Once the parfait is frozen solid, remove from the freezer, invert onto a flat plate and peel off the cling film. Heat a palette knife under the hot tap, dry, then run all over the sides of the parfait to smooth away the cling film marks. Pile the whole sweets on top, stand at room temperature for 5 minutes, then slice and serve.