In a small bowl
, stir together sour cream and baking soda. Set aside.
In a mixing bowl
, beat granulated sugar and butter with electric mixer on medium speed until well mixed. Beat in eggs and vanilla until well mixed. Add the flour
and baking powder; beat until well mixed. Pour the foamy sour cream mixture into batter; mix well.
For topping, in another bowl, combine brown sugar, cinnamon, and nuts
. Set aside.
Spread half of the batter into a greased 13x9x2-inch baking pan
. Sprinkle blueberries over batter. Sprinkle with half of the topping. Carefully spread remaining batter over all; sprinkle remaining topping over.
Bake in a 325 degree F oven for 55 to 60 minutes or until a wooden toothpick inserted near the center comes out clean. Serve warm or at room temperature. Makes 16 servings.