Use pears that are low in moisture content, such as Bosc pears.
Heat oven to 375 degrees. Spray a 9-by-4 1/2-by-2 3/4-inch loaf pan with vegetable spray, and set aside. In a medium mixing bowl, whisk together the flour, cornmeal, sugar, baking powder, baking soda, cinnamon, and salt. In a second medium mixing bowl, whisk together the buttermilk, eggs, egg white, and melted butter. Stir the buttermilk mixture into the dry ingredients. Stir in the pears and raisins until just combined.
Fill the prepared pan with batter. Place in the oven, and bake until a wooden skewer inserted into the center of the loaf comes out clean, 45 to 50 minutes. Remove the pan from oven, and transfer to a wire rack to cool. Serve with the Pear-Raspberry Butter.