01 - Preheat the oven to 375°F. Line a 12-cup muffin tin with paper liners or lightly grease with butter.
02 - In a large bowl, whisk together flour, sugar, poppy seeds, baking powder, baking soda, and salt until well combined.
03 - In a separate bowl, whisk eggs, Greek yogurt, melted butter, lemon zest, lemon juice, and vanilla extract until smooth and creamy.
04 - Pour the wet ingredients into the dry ingredients. Fold gently with a spatula until just combined. Do not overmix—the batter should remain slightly lumpy.
05 - Divide the batter evenly among the prepared muffin cups, filling each about three-quarters full.
06 - Bake for 16-18 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
07 - Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.
08 - Whisk together powdered sugar and lemon juice until smooth and pourable. Add more lemon juice if needed for desired consistency.
09 - Drizzle the glaze over the cooled muffins. Sprinkle with extra lemon zest if desired. Serve immediately or store in an airtight container.