FOR THE MUFFINS
2/3 cup sugar
Grated zest and juice of 1 lemon
2 cups all-purpose flour
2 teaspoons baking powder
¼ teaspoon baking soda
¼ teaspoon salt
3/4 cup sour cream
2 large eggs
1 teaspoon pure vanilla extract
1 stick (8 tablespoons) unsalted butter, melted and cooled
2 tablespoons poppy seeds
FOR THE ICING
1 cup confectioners’ sugar, sifted
2-3 tablespoons fresh lemon juice
GETTING READY: Center a rack in the oven and preheat the oven to 400 degrees F. Butter or spray the 12 molds in a regular-size muffin pan or fit the molds with paper muffin cups. Alternatively, use a silicone muffin pan which needs neither greasing nor paper cups. Place the muffin pan on a baking sheet.
BAKING: In a large bowl, rub the sugar and lemon zest together with your fingertips until the sugar is moist and the fragrance of lemon strong. Whisk in the flour, baking powder, baking soda and salt. In a large glass measuring cup or another bowl, whisk the sour cream, eggs, vanilla, lemon juice and melted butter together until well blended. Pour the liquid ingredients over the dry ingredients and, with the whisk or rubber spatula, gently but quickly stir to blend. Don’t worry about being thorough – a few lumps are better than over mixing the batter. Stir in the poppy seeds. Divide the batter evenly among the muffin cups.
Bake for 18 to 20 minutes, or until the tops are golden and a thick knife inserted into the center of the muffins comes out clean. Transfer the pan to a rack and cool for 5 minutes before carefully removing each muffin from its mold. Cool the muffins completely on the rack before icing them.
TO MAKE THE ICING: Put the confectioners’ sugar in a small bowl and add about 1 ½ tablespoons of the lemon juice. Stir with a spoon to moisten the sugar, then add enough additional lemon juice, a dribble at a time, to get an icing that is thin enough to drizzle from the tip of the spoon. You can then drizzle lines of the icing over the tops of the muffins or coat the tops entirely, the better to get and extra zap of lemon.