Double Lemon Poppy Seed Muffins

INGREDIENTS

• ½ cup + 1 tablespoon pure cane sugar
• 2 medium lemons, preferably organic (you’ll need the zest of both and the juice of one)
• 1½ cups white whole wheat flour
• ¼ cup poppy seeds
• 1½ teaspoon baking powder
• ¼ teaspoon baking soda
• ½ teaspoon fine-grain sea salt
• 5 tablespoons unsalted butter, melted and cooled
• ¾ cup plain yogurt (plain Greek yogurt works, too)
• 1 large egg (update 3/20/14: use 2 eggs for richer and slightly fluffier, more cupcake-like muffins)
• 1 teaspoon vanilla extract
• 2 teaspoons turbinado sugar for sprinkling on top