01 - Preheat the oven to 350°F. Grease and flour a 9x5-inch loaf pan or line it with parchment paper.
02 - In a medium bowl, whisk together the flour, poppy seeds, baking powder, baking soda, and salt. Set aside.
03 - Using an electric mixer, beat the softened butter and granulated sugar together until light and fluffy, about 3 minutes.
04 - Add eggs one at a time, beating well after each addition. Then mix in the lemon zest and vanilla extract.
05 - In a small bowl, blend together the freshly squeezed lemon juice and whole milk.
06 - With the mixer on low speed, add the dry ingredients to the wet mixture in three portions, alternating with the lemon-milk mixture, starting and ending with dry ingredients. Mix until just combined.
07 - Pour the batter into the prepared loaf pan and smooth the surface evenly.
08 - Bake for 45 to 55 minutes, or until a toothpick inserted into the center comes out clean.
09 - Allow the cake to cool in the pan for 10 minutes, then transfer it onto a wire rack to cool completely.
10 - Whisk powdered sugar with lemon juice until smooth and pourable. Drizzle the glaze over the cooled cake and let it set before slicing.