1. Preheat oven to 425°.
2. Place an 8-inch cast-iron skillet in preheated oven for 10 minutes.
3. Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, cornmeal, baking powder, and salt in a large bowl, stirring with a whisk. Combine yogurt, syrup, butter, and eggs, stirring with a whisk. Add yogurt mixture to flour mixture; stir just until moist (batter will be thick).
4. Remove pan from oven; coat pan with cooking spray. Spoon batter into preheated pan, smoothing top with a spatula. Bake at 425° for 20 minutes or until a wooden pick inserted in center comes out clean. Remove from oven; cool in pan on a wire rack 10 minutes.