Preheat your oven to 350°F (175°C).

If using fresh sweet potatoes, peel and boil until tender.

In a mixing bowl, mash the sweet potatoes until smooth.

Add sugar, milk, melted butter, eggs, vanilla extract, baking powder, salt, cinnamon, and nutmeg to the mashed sweet potatoes and mix thoroughly.

Transfer the mixture to a greased 9-inch baking dish.

Place the dish in the preheated oven and bake for about 40 minutes.

Insert a toothpick into the center; it should come out clean when done.

Let the souffle cool for a few minutes before serving.