1Preheat oven to 400°F. Coat 12 (1/2 cup size) muffin cups with cooking spray or line with paper liners.
2Whisk 1/2 cup sugar, yogurt, oil, & egg, plus 2 tsps. of the lemon zest, lemon juice, and vanilla, in a medium bowl.
3Whisk together dry ingredients, in a large bowl. Add yogurt mixture, and fold in, until almost blended. Gently fold in chopped cranberries. Divide batter among muffin cups.
4Combine remaining 2 Tbs. sugar and 1 tsp. lemon zest, in a small bowl. Sprinkle evenly over tops of muffins. Bake, until golden brown, and they spring back lightly, to the touch, 20-25 minutes. Let cool, in pan, 10 minutes. Transfer to wire rack, to cool, for at least 5 minutes, before serving. Makes 1 dozen.