Cook bacon in large skillet until crisp, 6 to 8 minutes. Remove with slotted spoon to paper towel. Pour off all but 4 tablespoons bacon fat from skillet. Crumble bacon.
Add onion, peppers, scallions, garlic to skillet; sauté until onion is softened, 8 minutes. Add oregano, thyme, chili powder; cook 2 minutes.
Mix bread, bacon and onion mixture in large bowl. Add broth, nuts, salt and pepper (can be made ahead and refrigerated in covered dish for up to 2 days).
Heat oven to 375 degrees F. Coat 13 x 9 x 2-inch baking dish (or 12 x 8 x 2-inch dish) with cooking spray. Spoon dressing into dish. Cover with foil.
Bake at 375 degrees F for 20 minutes. Remove foil. Bake 15 minutes or until top is nicely browned.
