Preheat the oven to 375 degrees F and position the rack in the middle. Butter the rims of a 12-hole muffin pan and line the cups with papers (or grease generously).

Whip together the sour cream, milk, melted butter, egg and egg yolk, zest, and lemon juice in a blender (or use a beater or whisk), then pour into a big bowl. Dump the flour, sugar, baking powder, baking soda, and salt on top of the wet ingredients, Mix the dry ingredients a bit with your fingers before stirring together the whole bowl. Mix just until smooth and combined. Divide the butter berween the muffin cups.

Bake the muffins 10 minutes. Turn the pan and bake 5 more minutes. Check for doneness with a toothpick; bake a few minutes longer if still gooey on top. Bake until just done-these muffins are best before they get at all brown. Remove the muffin tin to a rack to cool while you prepare the lemon glaze.

Mix the lemon juice and sugar and warm in the microwave (about 1 minute) or on the stove until the sugar dissolves. Stir again. Hold each muffin by the paper bottom and dip the top into the warm glaze. Let stand a moment before serving to absorb the glaze.

Muffin tin
12 large /18 medium muffins

1 1/2 cups sour cream
1/2 cup milk
1/2 cup plus 1 tablespoon butter, melted
1 egg plus 1 egg yolk
Grated zest of 1 1/2 lemons
1 tablespoon lemon juice
2 1/2 cups plus 2 tablespoons flour
1 cup plus 2 tablespoons sugar
1 1/2 teaspoons baking powder
1 1/8 teaspoons baking soda
1/4 teaspoon salt

Lemon Glaze:
1/2 cup lemon juice
1/2 cup sugar