Preheat oven to 375 degrees. Lightly spray a 12-count muffin pan with cooking spray. In a small bowl, combine flour, cornmeal, baking powder, baking soda, and salt. Place syrup and butter in a large bowl, and cream together using an electric mixer. Beat in eggs and yogurt. Fold in dry ingredients, mixing just until incorporated. Stir in raisins. Divide batter among muffin cups. Bake until a toothpick inserted into the middle of a muffin comes out clean, approximately 20 minutes. Allow to cool in pan briefly, then transfer muffins to a wire rack.