Preheat the oven to 425°F. Lightly grease a 9 or 10 inch cast iron skillet, or 8x8 square baking pan. In a bowl whisk together flour, cornmeal, baking powder, and salt. In another bowl whisk together melted butter, egg, honey, and milk. Add the butter mixture into the flour mixture, stirring until the batter is just combined, then fold in the blueberries. Pour into the skillet, smoothing out the batter. Bake for 30 to 35 minutes, or until the bread is golden and a tester comes out clean.