AT A GLANCE
|01||Preheat oven to 170C. For hazelnut topping, combine ingredients in a bowl, then freeze until required (this stops the topping melting into the cake when it’s baked).|
|02||Combine rhubarb and strawberry in a bowl with 1 tbsp of each sugar and set aside.|
|03||Beat butter and remaining sugars in an electric mixer until light and fluffy (4-5 minutes), add eggs one at a time, beating well after each addition. Stir in dry ingredients then buttermilk. Stir in one-third of rhubarb mixture, spoon into a 24cm-diameter cake tin buttered and lined on the base with baking paper. Scatter over remaining rhubarb mixture and hazelnut topping, bake until a skewer inserted withdraws clean (1¼-1½ hours). Cool in tin for 30 minutes, then on a wire rack to room temperature. Serve with crème fraîche.|
Note Rapadura sugar is available from select health-food shops and delicatessens. If unavailable, substitute dark brown sugar.