Preheat your oven to 375°F (190°C).

Peel and slice the sweet potatoes evenly, then boil them in a large pot for 10-15 minutes until tender.

Layer half of the sweet potato slices in a greased baking dish.

Sprinkle half of the cranberries over the sweet potatoes.

In a mixing bowl, combine heavy cream, brown sugar, cinnamon, salt, and pepper, then whisk until smooth.

Layer the remaining sweet potato slices and cranberries on top, then pour the remaining cream mixture over them.

Sprinkle Gruyère cheese and breadcrumbs on top.

Bake for 30-35 minutes or until the top is golden brown and edges are bubbling.

Let cool for a few minutes before serving.