Preheat oven to 375°F. Coat a 2-1/2 quart baking dish with cooking spray. Spread bread cubes in single layer on ungreased jellyroll pan. Bake, stirring often, until toasted and crisp, about 10-12 min. Cool.
In large skillet over medium heat, add pecans, cook, stirring, until lightly browned. Remove from skillet and reserve. In same skillet, melt 6 Tbsp. butter over medium heat. Add onion and celery, cook, stirring until tender. Add pears, cook until just starting to soften, 3-5 min. Add 1/4 cup chicken broth. Cook until reduced by half, 1 min. Stir in rice, 3 Tbsp. marjoram, salt and pepper until well blended. Transfer mix to large bowl. Cool slightly. Stir in toasted bread and pecans. Gradually stir in broth until moistened.
Transfer to baking dish. Dot with remaining 2 Tbsp. butter. Cover, bake 30 min. Uncover, bake until top is crisp, about 15 min. Serve sprinkled with remaining 1 Tbsp. marjoram.