Preheat your oven to 350°F. Butter and flour a 9x5 inch loaf pan, and set aside.* You can make this quick bread in an 8x4 inch pan, but it will take slightly longer to bake.
In a medium sized bowl, combine 2 & 1/4 cups flour, baking powder, cornstarch, and salt. Whisk, and set aside to prep the wet ingredients.
In a large bowl, pour in your milk, Greek yogurt or sour cream, sugar, vegetable oil, eggs, lemon zest and juice, and vanilla. Whisk to combine.
Combine your wet and dry ingredients. Fold together until you no longer see any dry clumps of flour. Take care not to over mix!
In a medium bowl, combine blueberries and remaining 1 tablespoon of flour. Toss together until the blueberries are all coated in four. Fold the blueberries into your quick bread batter.
Pour the batter into your prepared loaf pan. Bake in the center of your preheated 350°F oven for 50 to 60 minutes, or until golden brown on top and a toothpick inserted into the center comes out clean. If you notice the loaf browning too quickly, loosely tent some aluminum foil over the top and continue baking until cooked through.
Cool for about 15 minutes in your pan, then turn out onto a wire rack to cool enough to handle, or completely to room temperature. Serve warm or room temperature.