01 - Preheat your oven to 350°F. Thoroughly grease a 9x5-inch loaf pan, then line it with parchment paper, ensuring an overhang for easy removal. This prevents sticking and makes cleanup simpler.
02 - In a medium mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until well combined. Set aside.
03 - In a large mixing bowl, using an electric mixer or whisk, cream together the softened unsalted butter and granulated sugar until the mixture is light, fluffy, and pale in color, typically taking 2 to 3 minutes.
04 - Gradually beat in the large eggs, adding one at a time and mixing thoroughly after each addition. Once eggs are incorporated, stir in the lemon zest, fresh lemon juice, and vanilla extract until just combined.
05 - Add half of the prepared dry flour mixture to the wet ingredients and mix on low speed until just incorporated. Follow this by adding the whole milk, mixing gently. Finally, add the remaining flour mixture and mix until the batter is just combined. Avoid overmixing to ensure a tender crumb.
06 - Carefully pour the batter into the prepared loaf pan, spreading it evenly with a spatula. Bake for 50 to 55 minutes, or until a wooden skewer or toothpick inserted into the center emerges clean, indicating the cake is fully cooked.
07 - Allow the baked lemon loaf cake to cool in its pan for 10 minutes. Then, using the parchment paper overhang, carefully lift and transfer the cake to a wire rack to cool completely before proceeding.
08 - While the cake cools, prepare the icing. In a small bowl, whisk together the sifted powdered sugar, fresh lemon juice, and lemon zest until a smooth, pourable consistency is achieved. Adjust the consistency by adding more lemon juice if needed, a teaspoon at a time.
09 - Once the loaf cake is completely cool, generously drizzle the prepared lemon icing over the top. Allow the icing to set for a few minutes before slicing and serving.