Mashed Sweet Potatoes:

1. Preheat the oven to 375 degrees F (190 C). Wash, peel, and chop the 2 lbs of sweet potatoes into large chunks.
2. Bring a large pot of water to a boil, and add the chopped potatoes. Boil for 10 minutes until tender.
3. Once the potatoes are soft, drain the water from the pot. Add in 2 tbsps of butter, 1/3 cup of heavy cream (or plant milk), 1 tsp of pumpkin pie spice, 2 tbsps of brown sugar, 1 tbsp of maple syrup, 1 tsp of vanilla extract, and ½ tsp of salt.
4. Using a potato masher, mash the potatoes until smooth and all the ingredients are combined.
5. Transfer the mashed potatoes to an 8×8 baking dish.
6. To a medium bowl, add ¼ cup of chilled butter, ¼ cup of brown sugar, ¼ cup of all-purpose flour, ½ tsp of pumpkin pie spice, and ¼ tsp of salt. Use a fork to combine. Then add in ½ cup of pecans.
7. Sprinkle 1 ½ cups of marshmallows over the sweet potato mash and add spoonfuls of the streusel evenly on top of the casserole. Then add the remaining 1 ½ cups of marshmallows over the top to cover the sweet potatoes. 
8. Bake for 20 minutes. If necessary, broil at the end for 1 to 2 minutes until the marshmallows are toasted to your liking. Make sure to keep your eyes on it so it does not burn!
9. Allow it to cool for about 5 minutes before serving. Happy holidays!