Ingredients:
For the cake:
140g unsalted butter, softened, plus a little for greasing
140g golden caster sugar
1 whole egg
2 egg yolks, beaten
½ tsp vanilla extract
100g self raising flour
100g ground almonds
1 tsp baking powder
½ tsp ground nutmeg
1 large Bramley apple (about 200g), peeled and sliced (to give about 140g)
125g blackberries

For the mallow and to finish:
25g blackberries
100g white caster sugar, plus 1 tsp for the ripple
2 egg whites
1 tsp lemon juice
A little icing sugar to dust (optional)

Method:
1. To start, make the blackberry sauce to ripple through the mallow. Place the berries and 1 teaspoon sugar in a small bowl and cover with cling film. Microwave for 30 seconds on a high power. Alternatively, add 1 teaspoon water and soften in a pan over a low heat. Stir well until the mixture resembles a sauce, then leave to cool.

2. Heat oven to 160°C (140°C fan/gas 3). Grease and line the base and sides of a 23cm square traybake tin, leaving some overhang to make it easy to lift the bake out later. Using a hand whisk, beat the butter and sugar in a large bowl until pale and creamy, then add the egg and yolks, followed by the vanilla. Mix the flour, almonds, baking powder, nutmeg and a pinch of salt in a small bowl, then fold into the mix to make a thick batter.

3. Fold in the apple, spoon into the tin and smooth over the top. Scatter with the remaining blackberries, poke them in just a little, then bake for 45 minutes until golden and a skewer inserted into the middle comes out clean. Remove from the oven, but leave the oven on.

4. For the mallow topping, you’ll need a large piping bag with a 1cm nozzle, or a food bag with a corner snipped off. Whisk the egg whites, lemon juice and a pinch of salt to stiff peaks. Add the sugar 1 tablespoon at a time, whisking well after each spoonful to make a shiny, stiff meringue. Ripple with the cooled blackberry sauce, then spoon into the bag. Pipe 16 evenly spaced meringues on top of the cake (you’ll have some meringue mixture left over), then bake for 10-12 minutes until the meringues are just set. Leave to cool in the tin for approximately 30 minutes, then remove to a rack to cool completely.

5. Add a dusting of icing sugar then cut into squares and serve.