Apple-Sage Stuffing Cups

Ingredients

• 12 ounces sourdough bread, cut into 1/2-inch cubes (about 8 cups)
• 1 1/2 tablespoons butter
• 1 1/2 cups diced apple
• 1 1/4 cups prechopped onion
• 2/3 cup prechopped celery
• 1 1/2 tablespoons chopped fresh sage
• 1/2 teaspoon freshly ground black pepper
• 1/4 teaspoon kosher salt
• 1/4 cup chopped fresh flat-leaf parsley
• 1 3/4 cups unsalted chicken stock (such as Swanson)
• 2 large eggs, lightly beaten
• Cooking spray