175g unsalted butter, softened, plus extra for greasing
150g golden caster sugar
3 medium eggs, beaten
250g plain flour
1 tsp baking powder
pinch of salt
50g ground almonds
120ml sour cream, at room temperature
75g soft light brown sugar
75g plain flour
1tsp ground cinnamon
50g finely chopped almonds
40g unsalted butter, melted
1. Preheat the oven to 180ºC/350ºF/Gas mark 4. Grease the base of a 23-cm (9-inch) spring-form tin with butter and line baking parchment.
2. Make the crumble topping first. Mix together the sugar, flour, cinnamon and almonds. Pour in the melted butter and mix until the crumble starts to clump together.Set aside.
3. Cut the plums into quarters, remove the stones and cut each quarter in half again.
4. Cream together the butter and sugar until pale and light. Gradually add the eggs, beating really well between each addition.
5. Sift together the flour, baking powder and salt. Add the almonds and stir to combine.
6. Fold one-third of the dry ingredients into the creamed mixture, followed by one-third of the sour cream. Repeat until all the dry ingredients and the sour cream have been incorporated.
7. Spoon the cake mixture into the prepared tin and level it out. Scatter half the crumble mixture over the top of the cake.
8. Arrange the plums, cut-side uppermost, over the crumble and top with the remaining crumble.
9. Bake on the middle shelf of the oven for about 11/2 hours, or until a skewer inserted into the middle of the cake comes out with a moist crumb.
10. Serve the cake warm with a good dollop of crème fraîche or vanilla ice cream.
The Feel-Good Cookbook by Ainsley Harriott (BBC Books, hardback £20)