Preheat oven to 350 degrees F. Spray a 9x5-inch loaf pan with nonstick spray.
Sift first four ingredients (dry) into a small bowl. Set aside.
In a large bowl, use an electric mixer to beat butter until creamy. Then beat in sugar until light and fluffy. Add eggs, beating in one at a time. Stir in dry ingredients and then banana.
Carefully stir in blueberries.
Pour batter into prepared loaf pan and bake 50 minutes. A toothpick inserted into the center should come out clean.
Let sit for 15 minutes, then remove from the pan to a wire rack to cool.