Preheat your oven to 350º F. Line a 9x5-inch loaf pan with parchment paper, lightly grease with nonstick spray.
In a medium bowl, combine the flour, baking soda, and salt. Stir with a whisk and set aside.
In a large mixing bowl, combine the butter and sugar. Beat with an electric mixer for 90 seconds until combined. Add the eggs and vanilla, and mix until combined, about 30 seconds.
Pour the mashed bananas into the butter mixture and beat until well combined, about 90 seconds.
Add flour mixture to the batter and mix just until the flour is incorporated, taking care not to overwork the batter.
Toss fresh blueberries in a tablespoon of flour. Stir into the batter using a rubber spatula.
Transfer the batter to the prepared pan and bake for 55 to 60 minutes or until a toothpick inserted into the center comes out with a few dry crumbs (try to find a spot without blueberries).
Cool the bread in the pan on a wire rack for 20 minutes. Remove the bread and cool completely on a wire rack.