Preheat oven to 350°F (175°C). Grease and flour a loaf pan.
In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
In a large bowl, beat sugar and butter until light and fluffy. Add eggs one at a time, beating well after each addition.
Mix in milk, lemon juice, lemon zest, and vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Pour batter into the prepared loaf pan and smooth the top.
Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.