Preheat oven to 375°F. Grease a 9x13 baking dish.

Roast or boil sweet potatoes until tender, then mash with butter, milk, maple syrup, salt, and pepper.

Stir in goat cheese and most of the thyme, reserving a pinch for topping. Taste and adjust seasoning.

Spread mixture into the dish. Mix panko with olive oil and sprinkle over the top.

Bake 20–25 minutes until topping is golden and edges bubble. Sprinkle remaining thyme before serving.