To make the filling: Divide the raspberries and apples between six small heatproof dishes/ramekins or place them in one large shallow pie dish. Sprinkle with caster sugar, orange zest and juice and water.
To make the crumble: Put the flour into a large bowl with the butter. Using your fingertips, rub in the butter until the mixture resembles rough breadcrumbs, then stir in the almonds and brown sugar.
Scatter the crumble over the fruit filling.
Place on the cooking grate and bake (in-direct method) on medium heat for 20 minutes until the top is golden and the apple and raspberry mixture is bubbling.
Leave to cool slightly before serving with custard or spoonfuls of crème fraiche.