In a large bowl, beat together the butter and sugars until fluffy.
Beat in the eggs, one at a time, until well incorporated.
Beat in the vanilla and salt.
In a medium bowl, mix the flour and baking powder.
Alternately mix the flour and the buttermilk into the butter mixture, in thirds.
Stir in the lemon juice and lemon zest.
In a small bowl, toss the blueberries together with 1 tsp flour. Gently fold the blueberries into the cake batter.
Scrape the cake batter into the prepared tins and bake for 30-35 minutes, or until a skewer inserted into the centre comes out clean. Let cool completely before frosting.
For the Cream Cheese Frosting:
Beat the cream cheese and butter together until well incorporated.
Beat in the icing sugar, vanilla, and cream.
Use about ¾ cup of frosting for the cake filling. Frost the top and sides of the cake with the remaining frosting. Decorate with lemon slices and a few blueberries.
Chill in the fridge for at least 30 minutes before slicing.
Recipe by Kiku Corner at https://www.kikucorner.com/2015/02/07/blueberry-lemon-birthday-cake-with-cream-cheese-frosting/