Serves 8
• 300g (2 cups) plain flour
• 30g unsalted butter, chilled and cut into small cubes
• 1½ Tbs brown sugar
• 2 tsp baking powder
• 125g unsalted butter, softened
• 220g (1 cup) caster sugar
• 3 eggs
• 250g (1 cup) sour cream
• 350g plums, halved and stoned
• 250g blackberries cream, to serve
1. Preheat the oven to 170°C. Lightly grease a 22cm-square cake tin and line with baking paper, letting the paper overhang slightly around the rim to assist with removing the streusel once cooked.
2. To make the topping, place 50g of the flour in a bowl, add the cold cubed butter and rub in until the mixture resembles coarse breadcrumbs. Mix in the brown sugar and set aside.
3. To make the cake, sift the remaining flour, the baking powder and a pinch of sea salt into a bowl. In a large bowl, cream the softened butter and caster sugar with electric beaters.