Prep the Sweet Potatoes

1. Before beginning this recipe you will need sweet potato puree. Preheat the oven to 400 degrees.
2. Line a baking sheet with foil and place 1-3 small to medium sweet potatoes on it. Prick with a fork in a couple of places on each potato.
3. Place in the oven and bake for 45-60 minutes (depending on how big your potatoes are). You want these to be fork tender - to check, press the back of a spoon on the hot potato or stick a fork in it - if the fork goes in easily and the potato gives when pressed with a spoon then the potato is finished. Remove and let cool for 30 minutes.
4. Once cooled slightly, carefully remove the skins and place them in a food processor. Blend for 1-2 minutes, until a smooth and creamy consistency is achieved without any lumps or strings. 
5. Store in an airtight container until needed. This can be done and kept in the fridge for 3-4 days if wanting to do it in advance.

Souffle 

1. Preheat your oven to 350°F (175°C). Grease a 2-quart baking dish and set it aside.
2. In a large mixing bowl, combine the sweet potato puree, melted butter, brown sugar, salt, cinnamon, and nutmeg. Mix until well combined.
3. Separate the eggs, placing the yolks in one bowl and the whites in another. Add the egg yolks and milk to the sweet potato mixture, and stir until smooth and well blended.
4. Using an electric mixer, beat the egg whites until stiff peaks form - about 3-5 minutes. This step is important as it gives the soufflé its airy texture.
5. Gently fold the beaten egg whites into the sweet potato mixture. Be careful not to overmix; you want to keep the mixture light and airy.
6. Pour the mixture into the prepared baking dish. Smooth the top with a spatula, and bake in the oven for 45-50 minutes, or until the soufflé is set and slightly golden on top.
7. Allow to cool slightly before serving.