Adjust oven rack to middle position and heat oven to 375 degrees. Peel, core, and cut 1 pear into 1/4-inch dice. Combine 5 tablespoons of butter, brown sugar, cranberries, pecans, oats, orange zest, cinnamon, diced pear, and salt in large bowl; set aside.
Slice remaining pears lengthwise into halves. With a small sharp paring knife and a spoon remove the core and seeds from each pear, leaving a round well for the filling.
Melt remaining tablespoon butter in 12-inch nonstick ovensafe skillet over medium heat. Once foaming subsides, add pears, cut side down, and cook until cut surface is golden brown, about 3 minutes. Flip pears, reduce heat to low, and divide the filling among the pears, mounding it on top of the indentation. Add maple syrup and 1/3 cup cider to skillet. Transfer skillet to oven, and bake until skewer inserted into pears meets little resistance, 35 to 40 minutes, basting every 10 minutes with maple syrup mixture in skillet.
Transfer pears to serving platter. Stir up to 2 tablespoons remaining cider into sauce in skillet to adjust consistency. Pour sauce over pears and serve.