01 -
Preheat the oven to 350°F (175°C). Line four 6-inch cake pans with parchment paper and spray with non-stick spray.
02 -
In a bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
03 -
In a separate bowl, cream the softened butter and sugar together until light and fluffy.
04 -
Add the eggs one at a time, mixing well after each addition. Then, mix in the sour cream, vanilla extract, and vinegar.
05 -
Alternately add the dry ingredients and buttermilk to the wet mixture, beginning and ending with the dry ingredients. Add the blue and violet food colorings to achieve the desired shade of blue.
06 -
Divide the batter evenly among the prepared cake pans and bake for 25-27 minutes, or until a toothpick inserted into the center comes out clean.
07 -
Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely.
08 -
To make the frosting, beat together the softened butter, cream cheese, vanilla extract, and almond extract until smooth and creamy.
09 -
Gradually add the powdered sugar and mix until the frosting reaches a smooth, spreadable consistency.
10 -
To assemble the cake, layer the cakes with frosting and fresh blueberries between each layer. Cover the entire cake with frosting and decorate with additional blueberries.