Preheat your oven to 350°F (175°C). Grease a standard loaf pan.
In a bowl, whisk together flour, sugar, baking powder, and salt.
In another bowl, melt butter and let it cool slightly. Add eggs one at a time, whisking well after each addition. Stir in milk, lemon juice, and zest.
Gently fold the wet mixture into the dry ingredients until just combined—lumps are okay.
Pour batter into the prepared pan and smooth the top. Bake for 50-60 minutes or until a toothpick comes out clean.
Allow to cool in the pan for 10 minutes before transferring to a wire rack.
