Add cubed sweet potatoes to a large stock pot and cover with water. Bring them to a boil, and let cook for 15-20 minutes... until they can easily be pierced with a fork.

Pre-heat your oven to 375 degrees. Once the sweet potatoes are cooked, drain the potatoes and transfer them to the bowl of a stand mixer. On low speed, using the paddle attachment, mix the potatoes for 2-3 minutes.

Next, remove the paddle attachment, and attach the whisk. Add the next 8 ingredients to the bowl (whole milk through egg) and process with the whisk attachment for 2-3 minutes.

Transfer the sweet potato mixture to a greased 9x13 baking dish. Bake for 20 minutes.

While the sweet potatoes are baking, add the ghee/butter, maple syrup, and walnuts to a skillet over medium heat on the stove. Stirring continually, cook until the maple syrup and ghee/butter have thickened up some... (about 10 minutes). Remove from the heat as soon as you see it start to thicken to avoid burning.

After 20 minutes in the oven, remove the sweet potatoes and top with maple walnuts. Return the pan to the oven for an additional 10 minutes. Serve immediately. Enjoy!