Preheat oven to 375 degrees F (190 degrees C). Grease an 8-inch square pan.
In a medium bowl, mix together the flour, baking powder, baking soda and salt. Set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla. Beat in the flour mixture alternately with the sour cream. Fold in the blueberries.
Spread the batter into the prepared pan.
Bake for 30 to 40 minutes in the preheated oven, or until a toothpick inserted in the center of the cake comes out clean.
Allow the cake to cool before serving.
Interesting Facts
Blueberries are rich in antioxidants, which help to protect the body from disease.
Blueberries are also packed with vitamins, minerals, and fiber.
This cake is best served warm with a scoop of vanilla ice cream or a dollop of whipped cream.