Lightly grease the stoneware of a medium sized (approximately 4 quart) slow cooker.
In the prepared stoneware, combine pears, cranberries, sugar and orange zest and juice. Stir to combine.
In a bowl, combine pecans, whole wheat and all-purpose flours, rolled oats, sugar and cinnamon. Using a pastry blender, 2 knives or your fingers, cut in butter until mixture resembles coarse crumbs. Sprinkle evenly over fruit.
Place a clean tea towel, folded in half (so you will have 2 layers), over top of the stoneware to absorb moisture. Cover and cook on High for 3 to 4 hours, until fruit is hot, tender and juicy.