Line the bottom and up the sides of a 5- to 6-quart slow cooker by criss crossing two foil strips then spray with cooking spray.
In a large skillet, cook sausage until browned and crumbly; drain.
Place waffle pieces in slow cooker and top with cooked sausage.
In a medium bowl, whisk together eggs, half-and-half, syrup, sage, salt and pepper. Pour over sausage and waffles. Top with cheese.
Cover and cook on low 5-6 hours or until set.
Remove slow cooker crock and let stand, uncovered, 15 minutes. Serve with additional maple syrup, if desired.