I found this in a book called "Southern Cakes" once. it's pretty good.
Shenandoah Valley Blueberry cake.
1 2/3 cups All-purpose flour.
1 1/2 teaspoons Baking Powder.
1/4 teaspoon salt.
1/3 cup Butter, softened.
3/4 cup plus 2 tablespoons sugar
1 egg.
1/3 cup Milk
1 cup fresh or frozen blueberries (do not thaw if frozen).
Preheat oven to 375 degrees F, and generously grease a 9 inch square pan.
Combine Flour, baking powder, and salt in a small bowl, and stir with a form to mix well.
In a medium bowl, combine butter and sugar and beat with a mixer at high speed until well combined.
Add the egg and beat well for 1 to 2 minutes. stopping to scrape down the bowl, until the mixture is smooth and light.
Stir in half the flour mixture, then half the milk, mixing just enough to keep the batter smooth and well combined.
Add the remaining flour, then the rest of the milk, mixing gently,
Stir int he blueberries.
Scrape batter into the prepared pan, and bake at 375 degrees for 30 minutes, or until the cake is golden, springs back when touched gently in the middle, and is pulling away from the side of the pan.
Serve right from the pan, or at room temperature, cut into small squares. If it's a round cake, let it cool in the pan on a wire rack or folded kitchen towel fr ten minutes, and then turn it out to cool on the rack, top side up.