Preheat your oven to 375°F (190°C). Grease your baking dish lightly with butter or cooking spray.

Peel the sweet potatoes and slice them into thin rounds, about 1/4 inch thick. Boil in a pot of water for 10-15 minutes until tender.

Layer half of the sweet potato slices in the greased baking dish, overlapping slightly.

Sprinkle half of the fresh cranberries over the first layer of sweet potatoes.

In a bowl, combine heavy cream, brown sugar, cinnamon, salt, and pepper. Whisk until blended. Pour half over the layers.

Repeat layering the remaining sweet potatoes and cranberries, then pour the rest of the cream mixture over.

Top with shredded Gruyère cheese and breadcrumbs.

Bake in the preheated oven for 30-35 minutes until golden brown and bubbling.

Let cool for 5-10 minutes before serving.