Preheat the oven to 350°F. Line a large baking sheet with parchment paper.
Using a serrated knife cut through the middle of the slider rolls. Place the bottoms side by side on the pan. Set the tops aside.
In a small saucepan over medium heat, melt together the softened butter, mustard, honey, poppy seeds, grated onion, Worcestershire sauce and garlic powder. Whisk until fully combined and slightly thickened then remove from the heat.
Brush the bottoms of the sliced rolls with about ⅓ of the seasoned butter.
Layer ½ of the cheese on the bottom, then arrange the turkey over the cheese. Break cheese slices when needed to fit.
Spread the turkey with cranberry sauce.
Top with the final layer of cheese. Brush liberally with butter mixture.
Place the tops over the cheese.
Brush the remaining seasoned butter on the top and all sides.
Cover loosely with foil. Bake covered for 20 minutes then uncover and bake for an additional 10-15 minutes or until the tops are lightly golden.
Cut apart and serve immediately with additional cranberry sauce, if desired.