Preheat the oven to 425°F and line your muffin pans with liners or spray them well with non-stick spray.
In a small bowl, mix together the room temperature greek yogurt and lemon juice.
½ cup greek yogurt, ½ cup lemon juice
Place the sugar in a small bowl and add the lemon zest to it. Rub this mixture together, between your fingers, to allow the lemon oils to permeate the sugar.
1 cup granulated sugar, 3 tablespoons lemon zest
Cream together the room temperature butter and the lemon sugar. Mix in the room temperature eggs, one at a time.
½ cup salted butter, 2 large eggs
Add the yogurt and lemon juice mixture to this bowl and combine this well.
In a separate large bowl, whisk together the flour, poppy seeds, baking powder, and salt. Make a well (hole) in the center of this dry mixture.
2 cups all-purpose flour, 2 Tablespoons poppy seeds, 2 teaspoon baking powder, ½ teaspoon salt
Pour the wet mixture (butter, yogurt, etc) into the well in the dry ingredients. Stir only to moisten (it is okay if there are still some small lumps). Do not over-mix, or the muffins will be tough.
Divide the batter equally among the 12 muffin cups. Smooth out the tops of the batter if desired.
At this point, I like to let the muffins sit on the counter for about 20 minutes before placing them in the oven. I find that they rise slightly higher if I include this step, but they will still be great without it.
Bake at 425°F for 5 minutes. Then, turn the oven down to 350°F and continue baking for another 12 to 15 minutes.
While the muffins are cooling, prepare the glaze by whisking together the powdered sugar, milk, and lemon juice. You may adjust the amount of lemon juice depending on how thin you’d like the glaze to be.
½ cup powdered sugar, 1 tablespoon lemon juice, 1 tablespoon whole milk
Allow the muffins to cool for at least 10 minutes before removing them from the pan and glazing them.
Use a fork to drizzle the glaze back and forth across the tops of the muffins.