01 - Preheat the oven to 350°F. Grease and flour a 9-inch round cake pan or line it with parchment paper.
02 - In a medium bowl, whisk together flour, poppy seeds, baking powder, and salt. Set aside.
03 - In a large bowl, beat the softened butter and sugar until light and fluffy, approximately 3 minutes.
04 - Add eggs one at a time, beating well after each addition. Stir in vanilla extract and lemon zest.
05 - Mix in half of the dry ingredients, followed by milk and lemon juice. Fold in the remaining dry ingredients gently to avoid overmixing.
06 - Pour batter into the prepared pan and smooth the surface. Bake for 40 to 45 minutes, or until a toothpick inserted in the center emerges clean.
07 - Allow the cake to cool in the pan for 10 minutes, then release onto a wire rack to cool completely before slicing.