Cook the sweet potatoes using your favorite method. I chop them up and boil them on the stove top in a big pot for 15 to 20 minutes, or until they are very soft when poked with a fork. Strain the potatoes and set them aside to cool.

Stir together the ingredients for the topping until it forms a sort of clumpy dough. Set aside until ready to use. Remember, this topping is optional so if you prefer the soufflé nice and fluffy and creamy without the nutty topping, feel free to skip it.

Preheat the oven to 350 degrees Fahrenheit.

When the potatoes are cool enough to handle, peel and discard the skins. Mash the potatoes and measure them to be sure you have about 7 cups worth (it doesn’t have to be exact). 

Transfer the mashed sweet potatoes to a high powered blender along with the rest of the ingredients. Blend on a low or medium-low speed until everything is completely combined and the mixture is very smooth. This may require starting and stopping the blender multiple times to give it a stir.

Pour the sweet potato soufflé mixture into a large (13” x 9”) casserole dish.

Sprinkle the streusel topping over the sweet potato mixture and bake on the center rack of the oven for 50 minutes, or until the soufflé has set up. Note: after about 30 minutes, remove the soufflé from the oven and cover it with foil. This will ensure the topping gets nice and crispy but does not burn.

Remove the casserole from the oven. Serve and enjoy!

Note: The soufflé will be even more flavorful after it sits for 12 hours or longer in the refrigerator. If you’re able to, make it 1 to 3 days in advance and reheat it in the oven on the day of your gathering.