Preheat your oven to 350°F and prepare a loaf pan by greasing it generously or lining with parchment paper. Position the rack in the center of your oven so heat circulates evenly around the entire loaf throughout baking.

In a small bowl, whisk together flour, baking soda, and salt until fully combined and no lumps remain. Set this dry mixture aside and allow it to rest while you prepare the wet ingredients for your quick bread.

Using an electric mixer or sturdy whisk, cream the softened butter and sugar together until pale and fluffy, approximately 2-3 minutes. This incorporates air into the batter, creating the tender crumb texture that defines exceptional quick bread baking.

Add eggs one at a time to the butter mixture, beating well after each addition to create an emulsified base. Stir in vanilla extract, then alternate adding the flour mixture and sour cream in three additions, beginning and ending with flour to maintain structure.

Gently fold in lemon zest, lemon juice, blueberries, and walnuts using a rubber spatula with careful, deliberate motions. Pour the batter into your prepared loaf pan, smoothing the top evenly so this cozy quick bread brunch recipe bakes uniformly.

Bake for 48-52 minutes until a toothpick inserted in the center emerges with just a few moist crumbs clinging to it. The top should be golden brown and spring back slightly when touched, indicating complete doneness without overdrying the interior.

Cool the bread in its pan for 15 minutes, then turn it out onto a wire rack to cool completely before slicing. This resting period allows the crumb structure to set properly, ensuring clean, beautiful slices for serving.