Prep the pan and oven: Heat the oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment, leaving overhang for easy lifting.
Lightly grease the sides.
Mix the dry ingredients: In a medium bowl, whisk together 1 1/2 cups all-purpose flour, 2 teaspoons baking powder, and 1/2 teaspoon salt. Set aside.
Combine the wet ingredients: In a large bowl, whisk 3/4 cup plain yogurt, 3/4 cup granulated sugar, 2 large eggs, 1 teaspoon vanilla, the zest of 1 large lemon, and 2 tablespoons fresh lemon juice.
Add the fat: Slowly whisk in 1/3 cup melted, cooled unsalted butter (or 1/3 cup neutral oil) until smooth and glossy.
Bring it together: Add the dry ingredients to the wet and whisk gently just until the flour disappears. Do not overmix.
Prepare the blueberries: Toss 1 to 1 1/4 cups blueberries with 1 tablespoon flour.
Fold them into the batter with a spatula, reserving a few to sprinkle on top if you like.
Fill the pan: Scrape the batter into the prepared pan and smooth the top. Scatter any reserved berries over the top.
Bake: Bake for 50–60 minutes, or until the loaf is golden and a toothpick inserted in the center comes out mostly clean with a few moist crumbs.
Cool: Let the loaf cool in the pan for 10–15 minutes, then lift out and transfer to a rack to cool completely.
Optional lemon glaze: Whisk 3/4 cup powdered sugar with 1–2 tablespoons lemon juice until pourable. Drizzle over the cooled loaf and let set for 10 minutes before slicing.