Preheat oven to 350°F. Lightly grease an 8 1/2 x 4 1/2-inch loaf pan with cooking spray or oil.

Mix dry ingredients:
 In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

Mash bananas & combine wet ingredients:
 In a large bowl, mash the bananas until mostly smooth. Whisk in the sugar and melted butter until well combined.

Add remaining wet ingredients:
 Whisk in the eggs, Greek yogurt, and vanilla extract until smooth and fully incorporated.

Combine wet and dry:
 Add the dry ingredients to the wet ingredients and gently mix until just combined. Do not overmix.

Prepare blueberries:
 Toss the blueberries with the remaining 1 tablespoon of flour (this helps prevent sinking).

Fold in add-ins:
 Gently fold the blueberries and walnuts into the batter.

Transfer to pan:
 Pour the batter into the prepared loaf pan and smooth the top. Press a few extra blueberries on top for presentation.

Bake:
 Bake for 55–65 minutes, or until a toothpick inserted into the center comes out clean (a few moist crumbs are fine).

Cool:
 Let the bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.