Step 1

Preheat the oven to 375°F and set an oven rack in the middle position. Spray a 12-cup muffin tin with nonstick cooking spray.

Step 2

In a small bowl, combine the lemon zest, lemon juice, and milk. Let sit until curdled, about 10 minutes.

Step 3

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

Step 4

Whisk the egg into the curdled lemon/milk mixture, then add to the dry ingredients along with the melted butter. Whisk until just evenly combined.

Step 5

Spoon the batter evenly among the muffin cups. Bake until lightly golden brown and a toothpick inserted in the center comes out clean, 20 to 23 minutes. Let the muffins cool in the muffin tin for a few minutes, then turn them out onto a wire rack to cool completely.

Step 6

Meanwhile, make the glaze: In a small bowl, whisk together the lemon juice and confectioners' sugar. Stir, adding more lemon juice or sugar as needed, until you have a glaze with the consistency of honey.

Step 7

Drizzle the warm muffins with the glaze. Let the glaze set for at least 15 minutes, then serve.