Preheat the oven to 350 degrees. Spray a loaf pan with cooking spray and set aside.

In a medium mixing bowl combine the flour, baking powder, baking soda, and salt.

Place sugar, lemon zest, and eggs into a large mixing bowl and beat with a whisk until the mixture is a light lemon color and thickened. Whisk in sour cream, 2 tablespoons of lemon juice, and butter.

Mix in the flour mixture in two additions. After it is well combined pour in the butter and mix well. Gently stir in the blueberries.

Pour the batter into the prepared pans and bake for 50 to 55 minutes, or until a toothpick inserted in center comes out clean.

Remove the bread from the pan and cool on a wire rack.