01 - Preheat oven to 350°F and grease and flour a 9x5-inch loaf pan or line it with parchment paper.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl until evenly mixed.
03 - In a large bowl, beat butter and sugar with an electric mixer until light and fluffy, approximately 2 to 3 minutes.
04 - Add eggs one at a time to the butter mixture, beating well after each addition, then stir in lemon zest and vanilla extract.
05 - In a small bowl, blend whole milk with fresh lemon juice.
06 - Add the flour mixture to the wet ingredients in three parts, alternating with the milk-lemon juice mixture, beginning and ending with flour; mix until just combined without overmixing.
07 - Pour batter into prepared pan and smooth the surface evenly.
08 - Bake for 45 to 55 minutes or until a toothpick inserted in the center comes out clean.
09 - Let the loaf cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.
10 - Whisk powdered sugar with 2 tablespoons lemon juice until smooth, adding more juice as needed to reach a pourable consistency.
11 - Drizzle the glaze evenly over the cooled loaf and allow it to set before slicing.