Heat oven to 350°F. Spray 8 or 9-inch round cake pan with nonstick cooking spray. In large bowl, combine flour, baking powder, onion salt and garlic powder; mix well.
In medium bowl, combine zucchini, yogurt, pimientos, Parmesan cheese, hot pepper sauce and egg; blend well. Add to flour mixture; stir just until dry ingredients are moistened. Spread batter evenly in sprayed pan.
Bake at 350°F. for 30 to 35 minutes or until toothpick inserted in center comes out clean. Sprinkle Swiss cheese over top; bake an additional 2 to 3 minutes or until cheese is melted. Cut into wedges. Serve warm.