1. Preheat oven to 180 degrees Celsius.

2. Slice around each nectarine from top to bottom with a sharp knife, separating the halfs with a quick twist. Use a teaspoon to scoop out the stone. Arrange the halved nectarines, cut side facing up, in a tight-fitting ovenproof dish or baking tray. Add the melted butter to the 15g caster sugar and spread it over the cut flesh and cavity of each nectarine. Add a squeeze of lemon juice.

3. First start to soften the nectarines in the preheated oven for 10 minutes (15 minutes for slightly underripe fruit).

4. To remove skin from hazelnuts, toast them in the preheated oven for 15 minutes until the skins darken in colour, then rub them together in a clean cloth, to release them from the skins.

5. Meanwhile, use a food processor to blitz the hazelnuts, then blitz the amaretti biscuits to a breadcrumb consistency (or if you don’t have a food processor, roughly chop the nuts with a sharp knife and bash the biscuits in a plastic bag using a rolling pin). Place the crumble mixture in a bowl. Melt together the butter and sugar and once fully combined, stir them through the crumble.

6. Remove the par-baked nectarines from the oven and place one or two blackberries in each cavity. Spoon a tablespoon of crumble topping over each nectarine.

7. Bake uncovered in the preheated oven for an additional 10 minutes, or until the flesh of the nectarine is softened, looks more juicy, and the crumble is golden in colour (the length of time required depends on how ripe the fruit is, but the best time to remove them from the oven is before the skin wrinkles and the flesh collapses).

8. Once baked, add two to four tablespoons of water (or a dash of liqueur) to the base of the dish to loosen any caramelized juices and then pour any juice over the baked nectarines. Serve with vanilla ice-cream, marcarpone or softly-whipped cream.