Preheat the oven to 180C / 350F / 160C fan forced. Grease and line an 8 inch spring form cake tin.
Sift together the flour, almond meal, baking powder and baking soda and set aside.
Beat together the butter and sugar until pale and creamy. Add the eggs, one at a time beating well between each. Mix through the lemon zest.
Fold in half of the flour mixture. Now fold through the sour cream, followed by the remaining flour mixture. Tip 1 punnet of blueberries in and gently mix through until just combined. Make sure not to over-mix.
Tip the batter into your prepared baking tin then spread to the edges and level out the top a little.
Bake for 20 minutes, before carefully piling the remaining blueberries in a single layer over the top of the cake.
Bake for a further 25-30 minutes or until a skewer comes out clean. Allow to cool for 5 minutes before removing the outer ring, then allow to cool completely on the base of the tin.
Dust with icing sugar, then serve with some whipped cream or ice cream.
For best results you should always weigh ingredients like flour and sugar. Kitchen scales like these are relatively cheap but if you can’t weigh the ingredients, use the spoon and level method (don’t scoop).
You can use frozen blueberries but don't take them out of the freezer until you are ready to add them to the cake batter, then bake the cake straight away. Mix the frozen blueberries with flour (2-3 teaspoons) to stop the colour from runnning into the cake batter too much.