01 - Preheat oven to 350°F and grease and flour a 9x5-inch loaf pan or line it with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, and salt; set aside.
03 - Using an electric mixer, beat softened butter and granulated sugar until light and fluffy, about 2 to 3 minutes.
04 - Incorporate eggs one at a time, beating well after each addition, then stir in lemon zest and vanilla extract.
05 - Combine whole milk and fresh lemon juice in a small bowl.
06 - Add the flour mixture to the wet ingredients in three additions, alternating with the milk-lemon juice mixture, beginning and ending with flour; mix until just combined to avoid overmixing.
07 - Pour batter into prepared pan, smooth the surface, and bake for 45 to 55 minutes or until a toothpick inserted in the center comes out clean.
08 - Allow the loaf to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.
09 - Whisk powdered sugar with 2 tablespoons of lemon juice until smooth, adding more lemon juice if needed to achieve a pourable consistency.
10 - Drizzle glaze evenly over the cooled loaf and let set before slicing.