Meanwhile, slice package of turkey sausage into 12 slices and flatten a bit. Preheat skillet to medium high, spray with cooking spray, and cook sausage 5-7 minutes per side or until done.
Open buns and place the bottoms in a 9x13 inch glass baking dish. Set out the tops cut side up.
Stir together 1/4 cup Dijon mustard and 1 Tablespoon maple syrup, and spread a thin layer on the inside top and bottom of each roll.
Place one quarter slice of cheese on the inside bottom of each roll, then top each with apple slices, dividing evenly between the sliders. Top each slider with sausage patties and one quarter slice of the remaining cheese. Then place the tops of the buns on top of the sandwiches.
In small bowl, mix together melted butter,1 Tablespoon Dijon mustard, and 1 Tablespoon maple syrup. Using a pastry brush, brush the tops of the rolls with all of the butter mixture.
Bake in the preheated oven for about 15-20 minutes or until the tops are lightly browned and crisp, and the cheese is melted.
Serve right away or cool and store in the freezer, thawing and reheating as needed.
I made this using one package of turkey sausages, but if you would like a heartier sandwich, use two packages and place two patties on each slider.