Method

• 1.
  Preheat oven to 180°C/160°C fan-forced. Grease a 20cm round springform pan with extra butter and line base with baking paper.
• 2.
  In a stand mixer fitted with the paddle attachment, cream the butter and sugar for 2-3 minutes, until pale, soft and creamy. Add the vanilla and the eggs one by one, beating after each addition until fully incorporated. Sift over the self-raising flour and cinnamon and add the orange zest. Mix until just combined, taking care not to overmix. Spoon into the prepared pan and smooth the top with a spatula.
• 3.
  For the blueberry layer, mix all ingredients in a medium bowl and scatter over the cake batter, starting from the outside and working your way inwards.
• 4.
  For the streusel topping, mix the sugar and flour in a medium bowl, adding a pinch of fine salt. Pour over the melted butter and stir to form a rough crumble. Sprinkle the streusel on top of the blueberry layer.
• 5.
  Bake for 45-55 minutes (or 1 hour 10 minutes if using frozen berries) until golden on top and a skewer inserted in the centre comes out clean. Remove from oven and leave to cool in pan on a wire rack for 10 minutes.
• 6.
  Meanwhile, for the jammy blueberry drizzle, place half the blueberries in a small saucepan with the sugar, orange juice and 2 tbs water. Cook over low heat for 10 minutes, or until blueberries are soft and bursting and syrup has reduced slightly. Add remaining blueberries and cook, stirring occasionally, for a further 5 minutes (15 minutes if using frozen berries), or until sauce thickens. Remove from heat and set aside to cool, then chill until ready to serve.
• 7.
  To serve, slice the cake into wedges and serve with the cream of your choice, with a big spoonful of jammy blueberries rippled on top.