Preheat oven to 325 degrees. Prepare a 9-inch loaf pan by coating bottom and sides with baking spray.
Using a colander, rinse and drain the fresh blueberries.
Make the Batter
In a small bowl, combine the all-purpose flour, baking powder, baking soda, and salt. Whisk together to combine. Set aside.
In a large mixing bowl, combine the granulated sugar, softened butter, and sour cream. Cream together on high speed until light and fluffy, 2-3 minutes.
Add in the vanilla and lemon extracts. Beat in large eggs, one at a time, mixing well after each addition, about one minute.
Reduce speed to low and gradually add in the flour mixture, beating until combined.
Prepare the Blueberries
In a small bowl, gently mix in 1 tablespoon of flour with the blueberries to prevent berries from sinking to the bottom of the cake. Using a rubber spatula, fold berries into the batter.
Spoon the batter into the prepared loaf pan, carefully spreading to the edges of the pan.
Bake in preheated oven for 60-65 minutes until center tests done with toothpick.
Allow the cake to cool for ten minutes before removing from pan. Carefully run a butter knife around the edges of the pan, and then turn the cake over. Turn cake upright and cool completely on a wire cooling rack.
Before slicing, sprinkle powdered sugar over the top. Slice into one-inch pieces, and if desired, serve with fresh fruit and/or whipped cream. Serves 10-12.
Notes
*Unless otherwise indicated all butter on this recipe site is salted.