Set your oven to 350°F (175°C) and lightly grease a 9x5-inch loaf pan to prevent sticking.
For easy release, line it with parchment paper.
In a medium bowl, thoroughly whisk the flour, baking powder, and salt until evenly incorporated.
In a large bowl, cream the butter and sugar together for 3-5 minutes until the mixture becomes pale, light, and fluffy. This helps create a soft, moist texture.
Add the eggs one at a time, then mix in lemon zest and juice for a refreshing citrus flavor.
Gradually alternate adding the dry ingredients and sour cream, mixing gently to keep the batter light.
Toss the blueberries in a little flour, then fold them into the batter carefully.
Pour the batter into the greased pan and bake for about 60 minutes. To ensure it's done, insert a toothpick into the center; it should come out clean or with slight moist crumbs clinging to it.
Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing and enjoying!