Preheat the oven to 425°F. Line a 12-cup muffin pan with paper liners.

In a large bowl, whisk together the flour, granulated sugar, poppy seeds, salt, baking powder, and baking soda.

In a separate bowl, whisk together the Greek yogurt, milk, lemon zest, lemon juice, melted butter, eggs, and vanilla extract until smooth.

Add the wet ingredients to the dry ingredients.

Gently stir with a spatula just until combined. Do not overmix.

Divide the batter evenly among the 12 muffin cups.

Bake for 15–17 minutes, or until the tops are lightly golden and a toothpick inserted into the center comes out clean or with a few moist crumbs.

Let the muffins cool in the pan for about 10 minutes, then transfer them to a wire rack to cool completely.

To make the glaze, whisk together the powdered sugar and fresh lemon juice until smooth.

Drizzle the glaze over the cooled muffins.

Let the glaze set slightly before serving.