Directions:

Preheat oven to 375 degrees F

Lightly spray rimmed baking sheet with nonstick cooking spray and line with parchment paper.

In a large bowl stir together butter, olive oil, parmesan cheese, chopped rosemary, salt and pepper.

Add sweet potatoes and toss to coat evenly.

Stack 3 to 4 potato slices onto the baking sheet and insert skewer through the center to the bottom of the stack. Make 12 stacks.

Bake for about 40 minutes until the potatoes are tender and golden brown.

Remove from the oven and quickly skatter more parmesan cheese and chopped rosemary over the stacks. Place on a serving tray and serve while hot.