Preheat oven to 400 degrees F. Place 1 tablespoon of butter in a 10 inch cast iron skillet and place in the oven while preheating. Or use a 9x9 pan lightly greased (don't place in oven while preheating).

In a large bowl combine the cornmeal, flour, sugar, baking powder and salt. Add in the buttermilk, eggs and melted butter. Stir until almost combined and add in the blueberries and peaches. Gently stir just until combined. Spoon into hot skillet or prepared baking pan. Bake for 20-25 minutes or until toothpick inserted in center comes out clean.