Preheat oven to 400°F and place a rack in the center. Prepare a 12-cup muffin pan by spraying with nonstick spray or lining with paper muffin cups; set the pan on a baking sheet.
In a large bowl, whisk together 1 cup all purpose flour, 1/3 cup whole wheat flour, 1/3 cup yellow cornmeal, 1/3 cup old fashioned oats, 1/4 cup granulated white sugar, 2 teaspoons baking powder, and 1/4 teaspoon baking soda.
In a separate bowl, whisk together 1 cup low fat buttermilk, 1/3 cup pure maple syrup, 2 large eggs, and 1/2 cup (1 stick) unsalted butter (melted and cooled) until blended.
Pour the liquid mixture into the dry ingredients and stir gently until just incorporated; the batter should be lumpy—do not overmix.
Stir in 3/4 cup chopped dried fruit until evenly distributed.
Divide the batter evenly among the 12 muffin cups.
Bake for 18 to 20 minutes, or until the muffin tops are golden and a thin knife inserted into the center comes out clean.
Transfer the pan to a cooling rack and let the muffins cool in the pan for 5 minutes, then carefully lift each muffin out of its mold and place on the rack to finish cooling.