Preheat the oven to 400F. Spray an 8x8 baking dish with olive oil spray.
In a medium saute pan, crumble the sausage and brown it, stirring frequently, for about 8 minutes. Remove from the pan with a slotted spoon and drain on a plate with a paper towel. Toss the diced celery and onion into the hot pan for 3-4 minutes to softened.
In a large bowl, combine the cooked rice, browned sausage, cooked celery, onion and garlic, chicken broth, salt, sage, black pepper, garlic powder, Italian seasoning, almond slivers and diced apple. Mix well.
Pour the stuffing into the prepared pan and cover with aluminum foil. Bake for 20 minutes, then remove the foil and bake for an additional 5 minutes. Remove from the oven and serve.