1. Preparation
Preheat your oven to 350°F (175°C).
Line a muffin tin with paper liners or lightly grease it with cooking spray.
In a medium bowl, whisk together the flour, poppy seeds, baking powder, baking soda, and salt. Set aside.
In another bowl, combine the sugar and lemon zest, rubbing the zest into the sugar to release the oils.
Add the eggs to the sugar and lemon mixture, and whisk until well combined.
Mix in the yogurt, lemon juice, and melted butter, combining until smooth.
2. Cooking
Gradually add the dry ingredients into the wet ingredients, mixing just until combined. Be careful not to overmix; a few lumps are okay.
Scoop the batter into the prepared muffin tin, filling each cup about 2/3 full.
Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted in the center of a muffin comes out clean.
Once done, remove from the oven and allow the muffins to cool in the pan for 5 minutes.
Transfer the muffins to a wire rack to cool completely.