Preheat oven to 375° F. Line muffin pan with muffin-cup liners; coat with cooking spray.
In a large bowl combine flour, sugar, baking powder and salt. Make a well in center of the mixture and set aside.
In a medium bowl, combine ricotta, water, olive oil, orange zest, orange juice, and egg. Add ricotta mixture to the well in the flour mixture. Stir just until moistened.
Divide batter evenly among muffin cups. Sprinkle turbinado sugar over batter. Bake for 14-16 minutes, or until a toothpick inserted in center comes out clean. Cool 5 minutes in pan on a wire rack.