Preheat oven to 350F and grease a 9 x 11 casserole dish.

Peel and chop sweet potatoes into large chunks.

Heat a large pot of water and bring to a boil. Add sweet potato chunks and cook 22-25 minutes or until fork tender. Drain and let cool 15 minutes.

While potatoes are cooling, make topping. Mix together brown sugar, pecans, flour, cinnamon, and salt. Add in melted butter and stir until combined. Add in marshmallows and mix up.

Mash sweet potatoes using a potato masher until mostly smooth. Add butter to the sweet potatoes and continue to mash. Stir in whisked eggs, brown sugar, salt, cinnamon, and nutmeg.

Pour sweet potato mixture into prepared casserole dish. Evenly top with crumble topping.

Bake uncovered for 35-40 minutes, and if marshmallows begin to brown too much, loosely cover with aluminum foil spray with non-stick spray.

Let cool 10 minutes before serving.