Preheat your oven to 375°F (190°C). Gather your ingredients and grease the baking dish.

Peel and slice the sweet potatoes into even rounds, about 1/4 inch thick. Boil slices in salted water for 10 to 15 minutes until fork-tender.

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

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

In a medium bowl, whisk together heavy cream, brown sugar, cinnamon, salt, and pepper. Pour half of this mixture over the layers.

Repeat by layering the remaining sweet potatoes, cranberries, and the rest of the cream mixture.

Top with Gruyère cheese and breadcrumbs, then bake for 30 to 35 minutes until golden brown and bubbly.

Let cool for 10 minutes before serving to allow flavors to meld.