First, cream together the butter and sugar, then add the eggs, sour cream, and vanilla extract. Beat well and gradually add the sifted flour, baking powder and baking soda.
Mix until well blended.
Place half the mixture into a 9x13 inch greased baking pan, or an angel cake pan.
Sprinkle ½ a cup of blueberries on top of the mixture.
Place the remainder of the batter on top, and sprinkle with the remaining blueberries.
Bake in a preheated oven at 350F for 45 minutes or until done. Powdered sugar may be sprinkled on top when cool.