Preheat your oven to 325°F. Grease a standard loaf pan well and optionally line it with parchment.

In a bowl, whisk flour, baking powder, and salt together and set aside.

In a large mixing bowl, beat the softened butter and granulated sugar until pale and fluffy.

Add eggs one at a time, mixing well after each addition. Scrape down the bowl as needed.

Mix in the vanilla, lemon zest, and lemon juice until blended.

Add the dry ingredients in three parts, alternating with the milk. Start with the flour, then milk, and repeat till all is combined.

Toss the blueberries with 1 tablespoon of flour and gently fold them into the batter.

Spoon the batter into the prepared loaf pan and smooth the top.

Bake for 70 to 85 minutes or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool the cake in the pan for 15 minutes before lifting it out to cool completely on a wire rack.

Once cool, prepare the optional glaze by whisking together the powdered sugar, lemon juice, and a pinch of zest.

Drizzle the glaze over the cooled pound cake before serving.