01 - Preheat oven to 350°F. Grease and flour a 10 to 12-cup Bundt pan thoroughly.
02 - Whisk together flour, baking powder, baking soda, salt, and poppy seeds in a medium bowl.
03 - Beat butter and sugar on medium speed until light and fluffy, about 3 to 4 minutes.
04 - Add eggs one at a time, mixing well after each. Stir in lemon zest and vanilla extract.
05 - Combine lemon juice and milk in a separate measuring cup.
06 - On low speed, add flour mixture and milk-lemon juice alternately to batter, starting and ending with flour. Mix until just blended; avoid overmixing.
07 - Pour batter evenly into prepared Bundt pan and smooth top with a spatula.
08 - Bake for 45 to 55 minutes or until a skewer inserted in the center comes out clean.
09 - Let cake cool in the pan for 15 minutes before inverting onto a wire rack to cool completely.
10 - Whisk powdered sugar, lemon juice, and lemon zest until smooth and drizzle over cooled cake. Allow glaze to set before serving.