Preheat the oven to fan160C/ conventional 180C/gas 4 and butter and line the base of a loose-based 22cm round cake tin with non-stick baking paper or reusable Bake-o-glide.
Put the butter, sugar, eggs,flour, baking powder and vanilla in a bowl. Beat with a wooden spoon for 2-3 minutes, or with a hand electric beater for 1-2 minutes, until lighter in colour and well mixed. Beat in 4 tbsp soured cream, then stir in half the blueberries with a large spoon.
Tip the mixture into the tin and spread it level. Bake for 50 minutes until it is risen, feels firm to the touch and springs back when lightly pressed. Cool for 10 minutes, then take out of the tin and peel off the paper or lining. Leave to finish cooling on a wire rack.
To make the frosting, beat the soft cheese with the icing sugar and the remaining soured cream in a bowl until smooth and creamy. Spread over the top of the cooled cake (don't be impatient as the frosting will melt if the cake is too warm) and scatter with the remaining blueberries. The cake will keep in the fridge for a couple of days. Bring it to room temperature for about an hour before serving.
The fashionable blueberry (Vaccinium myrtillus) is a relative newcomer to the popular fruit scene and was one of the first to be titled a ‘superfood’. There are many different varieties of blueberry growing in different regions of the world. Huckleberries and bilberries are well known members of the blueberry family, native to North America.
Blueberries grow in clusters on shrubby bushes and can range in size. Some grow in the UK, but the majority of the blueberries we find in the shops will be imported. Cultivated blueberries are common and taste sweeter than those grown in the wild which are tart. Blueberries are a deep blue-purple colour with a thin translucent skin and tiny seeds.
Blueberries are extremely rich in phytochemicals, naturally occurring plant compounds, such as ellagic acid and anthocyanidins which are responsible for the blue, indigo and red colouring. Phytochemicals have been extensively researched for their antioxidant action that helps protect the body against a long list of diseases. However, it is important to note that their superfood label is somewhat over the top and should encompass all berries, not just blueberries.
Research has shown that anthocyanidins are highly active phytonutrients transported in the bloodstream where they act on blood vessels and collagen to reinforce and preserve it. They support blood vessel integrity around the body, not only the collagen in skin. This action has linked anthocyanidins to a reduction in cardiovascular disease (by protecting the vessels around the heart).
Another popular use of blueberries is related to vision and protecting against age-related macular degeneration. Legend suggests that during World War Two, British Air Force aviators ate bilberry jam daily to improve their night vision…
Select and store
Choose blueberries that look firm and free from moisture, since the presence of moisture will cause them to spoil. Store in the fridge where they will keep, although they are best if consumed within a few days.
Before freezing, spread the berries out on a baking sheet and place in the freezer until frozen. Once frozen, put them in a plastic bag for storage. Frozen blueberries may lose their texture more than other fresh berries, but the flavour still remains good.