Put the butter, sugar, vanilla extract, eggs, flours, baking powder and bicarbonate of soda. Beat with a electric mixer until well combined and looks pale. Beat 4 tbsp of soured cream and stir in half of the blueberries.
Tip the mixture into the tin, level it and bake it for 50 minutes, or until a skewer inserted comes out clean.
Cool in the tin for 10 minutes, then remove it from the tin, peel the paper. Then leave it in the wire rack to cool completely.
Beat together the soft cheese, icing sugar, soured cream until it looks creamy and smooth. Spread over the top of the cake and scatter the blueberries.
You can also make like a blueberry sauce, by heating the blueberries with some honey, until the berries get mashed up, pour it on top of the cake.