01 - Set the oven to 375°F. Line a 12-cup muffin tin with paper liners or grease thoroughly.
02 - In a large mixing bowl, whisk together flour, sugar, poppy seeds, baking powder, baking soda, and salt until evenly blended.
03 - In a separate bowl, beat eggs with milk, melted butter, lemon juice, lemon zest, and vanilla extract until homogeneous.
04 - Fold wet ingredients into dry using a spatula until just combined; do not overmix—some lumps are acceptable.
05 - Distribute batter evenly into prepared muffin cups, filling each approximately three-quarters full.
06 - Bake for 16 to 18 minutes or until a toothpick inserted in the center emerges clean.
07 - Let muffins cool in the tin for 5 minutes before transferring to a wire rack to cool thoroughly.
08 - Whisk powdered sugar with 2 tablespoons lemon juice until smooth; adjust consistency with additional juice if needed.
09 - Drizzle glaze over fully cooled muffins and allow to set for 10 minutes prior to serving.