Preheat your oven to 375°F (190°C).

In a large pot, add peeled and sliced sweet potatoes and cover them with water. Bring to a boil and cook for 10-15 minutes until just tender, then drain and set aside.

Grease a baking dish with a bit of butter or cooking spray. Layer half of the boiled sweet potato slices in the dish, slightly overlapping.

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

In a medium bowl, whisk together the heavy cream, brown sugar, ground cinnamon, salt, and pepper until well combined.

Pour half of the cream mixture over the first layer of sweet potatoes and cranberries, ensuring even distribution.

Repeat the layering process with the remaining sweet potato slices and cranberries, then pour the rest of the cream mixture on top.

Sprinkle the shredded Gruyère cheese and breadcrumbs over the top.

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

Let cool for a few minutes before serving.