Preheat your oven to 350°F (175°C). Grease and flour a 9x5 inch loaf pan.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

In a large mixing bowl, cream the softened butter and granulated sugar together until light and fluffy.

Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Gradually add the dry ingredients to the butter mixture, alternating with the buttermilk. Begin and end with the dry ingredients. Mix just until combined.

Fold in the lemon zest and lemon juice gently until evenly distributed in the batter.

Pour the batter into the prepared loaf pan. Smooth the top with a spatula.

Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean.

Once baked, remove from the oven and allow to cool in the pan for about 10 minutes. Then, transfer to a wire rack to cool completely.

While the loaf cools, prepare the glaze. In a small bowl, whisk together the powdered sugar, lemon juice, and lemon zest until smooth.

Once the loaf is completely cooled, drizzle the glaze over the top, allowing it to drip down the sides.

Let the glaze set for a few minutes before slicing and serving.