Grate white bread on a grater. Spread the bread shavings on a baking tray lined with baking paper and roast in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 10-12 minutes until crispy. Stir 2-3 times so that they roast evenly. Put the crumbs in a bowl and mix with brown sugar and cinnamon
Wash the plums, drain, halve and stone them. Peel, core and slice apples. Mix plums, apples and sugar
Spread a third of the crumbs on 4 ramekins (each approx. 10 cm Ø). Put half of the fruit on top, then spread the second third of the crumbs on top. Layer the remaining fruit on top. Chop the hazelnuts and mix with the remaining crumbs. Melt butter and mix with the crumbs. Spread on the forms. Reduce oven temperature (electric cooker: 150 °C/ circulating air: 125 °C/ gas: see manufacturer). Bake the crumble for 30-40 minutes until the crumbs are crispy and golden in colour. Serve with whipped cream or vanilla sauce