1 cup all-purpose flour
1/2 cup sugar
1 tablespoon poppy seeds
3/4 teaspoon baking powder
3/4 teaspoon baking soda
1/4 teaspoon salt
1 egg
1/3 cup 1% buttermilk
1/3 cup reduced-fat plain yogurt
1 tablespoon canola oil
2 teaspoons lemon juice
1 teaspoon grated lemon peel
1/2 teaspoon vanilla extract
2 teaspoons confectioners' sugar, divided