This is a recipe that has developed over the years. It is not really a casserole, or souffle, but almost a mousse in texture. Very light and fluffy.
Begin by peeling and chopping 4 pounds sweet potatoes, then place the chunks in a large pot. Cover with water, bringing the pot to a boil. Cook until the chunks start to fall apart. Cook until almost a mush in consistency.
Drain, then transfer the potatoes to the bowl of your stand mixer. Add 1/4 of heavy cream, cover, then whip on high for several minutes. If you forget to cover, plan on spending several hours cleaning the walls, floors ceilings, you get the idea.
Add 1/2 stick butter
1/4 cup packed brown sugar
1/2 teaspoon cinnamon
1/4 teaspoon nutmeg
1/4 teaspoon ginger
A pinch of cloves.
Whip 3 more minutes.
Pour mixture into a casserole dish and sprinkle 1/4 cup of brown sugar mixed with 1/4 cinnamon on top.
Bake one hour at 250 degrees.
Increase temperature to 325 degrees and bake 30 minutes more.