Step 1

Coat a 5-quart slow cooker with cooking spray. In a large bowl, stir together the sweet potatoes, pecans, butter and orange juice concentrate until combined. In a small bowl, stir together the brown sugar, pumpkin pie spice and cayenne pepper. Sprinkle over the sweet potato mixture and stir until combined. Spoon into the slow cooker.

Step 2

Cover and cook on low for 2 to 3 hours.

Step 3

Sprinkle the marshmallows over the top of the sweet potatoes in the slow cooker. Cover and cook on low for 15 more minutes, or until the marshmallows are melted.