Preheat the oven to 350°F (177°C). Grease a 9x5 inch loaf pan.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large bowl, beat the butter and sugar together until light and fluffy, about 2-3 minutes. Beat in the whisked eggs one at a time, then stir in the milk, lemon zest, and lemon juice.
Fold the dry ingredients into the wet ingredients until just combined. Fold in the poppy seeds.
Pour the batter into the prepared loaf pan and bake for 55-65 minutes, until a toothpick inserted in the center comes out clean.
Allow the loaf to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.
