Preheat the oven to 450 degrees F. Spray a baking sheet with nonstick cooking spray, or line it with parchment paper.
In a nonstick skillet, heat oil over medium heat. Add onions and sauté until tender, about 3 minutes. Add apples and sauté for 3 to 5 minutes longer, or until the apples are very tender. Transfer to a large bowl and let cool completely.
To the cooled onion/apple mixture, add all remaining ingredients and mix well.
Divide the sausage mixture into 16 portions and form into ¾ inch thick patties. Place the patties on the prepared baking sheet and bake until the outside is golden brown and the interior is no longer pink, about 10 minutes.
Notes
The patties can be prepared ahead and stored, well wrapped, in the freezer for up to 3 months. It will take about 20 minutes for frozen patties to cook.
To make fresh breadcrumbs: Trim crusts from firm sandwich bread. Tear bread into pieces and process in a food processor until coarse crumbs form. One slice of bread makes about ⅓ cup crumbs.