Preheat oven to 350 degrees F (175 degrees C). Generously butter a 9x13-inch baking dish.
Place sweet potatoes in a large pot and cover with 2 to 3 inches of water; cover and bring to a boil. Reduce heat to medium-low and simmer until tender but still slightly firm in the center, about 12 minutes. Drain and cool.
Peel the sweet potatoes and cut into 3-inch chunks or thick slices; arrange in the buttered baking dish. Top with crushed pineapple (in its juice) and candied ginger.
Combine coconut milk, sugar, honey, butter, ground ginger, salt, and black pepper in a saucepan. Bring to a boil; reduce heat and simmer until slightly thickened, 5 to 10 minutes. Pour coconut milk mixture over sweet potatoes. Cover baking dish with aluminum foil.
Bake in the preheated oven until very tender, about 45 minutes. Remove foil, baste sweet potatoes with cooking liquid and continue baking until liquid is slightly thickened, 10 to 15 minutes.