In a mixing bowl, whisk together the cornmeal, flour, salt, and baking powder. In a separate bowl, combine honey or syrup and ½ cup melted butter. Stir until combined. Beat in 2 eggs. Mix in the yogurt/buttermilk/milk.
Add the wet ingredients into the dry ingredients and mix thoroughly. Add caramelized onions & corn. Preheat a heavy cast iron pan in the oven at 400 degrees. Add the remaining ¼ cup butter to the pan and be sure to wipe the sides of the pan with the butter using a brush or paper towel.
Add your batter to the prepared pan and bake at 400 degrees until edges pull away and a toothpick inserted comes out clean. The time varies depending on how many batches you make at once and how large of a pan you have (which determines the depth of the batter). For a bigger batch, drop temp halfway through to 375.