1. Preheat oven to 375°.
2. Coat 4 cups of a Texas-size muffin tin with cooking spray. Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, baking powder, and turbinado sugar in a medium bowl. Combine egg and yogurt in a small bowl; add yogurt mixture to flour mixture, stirring just until moistened. Spoon batter into prepared muffin cups; add water to unfilled cups to a depth of 1 inch. Coat batter with cooking spray.
3. Bake at 375° for 20 minutes or until cakes spring back when lightly touched. Cool cakes 1 minute in pan; remove cakes from pan, and cool 5 minutes on a wire rack.