Easy Sweet Potato Casserole with Marshmallows

1. Cook the Sweet Potatoes: Preheat the oven to 375 degrees F and set an oven rack in the middle position. Preheat the oven to 375 degrees F. Poke the sweet potatoes all over with a fork, and put them on a foil-lined half-sheet pan—Bake, turning once, until very tender, about 45 minutes to 1 hour. Remove from the oven and allow to cool. When the sweet potatoes are cool enough to handle, slice lengthwise and scrape the pulp out of the skin. Reduce the oven to 350 F degrees.
2. Alternatively, you can prick the sweet potatoes all over with a fork. Then, place them on a microwave-safe plate and microwave on high (100% power) until the sweet potatoes are very soft when giving them a squeeze, about 12 to 14 minutes, rotating the plate one quarter turn every 3 minutes or so.
3. Let it stand for five minutes. Then, cut the potato lengthwise, scrape the pulp out of the skin, or peel them. Or peel and cut the sweet potato into 1-inch chunks. Bring a large pot of water to a boil (don't add salt). Add the sweet potatoes and cook until soft and very tender, 20 to 25 minutes. Drain and let cool.

Make the Pecan Streusel:

1. Meanwhile, whisk the flour, light brown sugar, and cinnamon together in a medium bowl. Cut the butter into the flour mixture with a pastry cutter or fork until resembles coarse crumbs. Mix in the chopped toasted pecans; set aside.
2. Prepare the  Sweet Potato Casserole:
3. In the bowl of the stand mixer with the paddle attachment, add the cooked sweet potatoes and beat until smooth. Add the butter, condensed milk, nutmeg, and vanilla extract on medium speed until smooth and creamy, about 2 minutes. Taste and adjust the sweetness with light brown sugar if necessary. Beat in the eggs until well combined and smooth.
4. Transfer the sweet potato mixture to a 2-quart baking dish and spread evenly. Sprinkle the topping evenly over the sweet potato mixture and bake, uncovered, for about 3o to 40 minutes, or until the topping is nicely browned.
5. Remove the pan from the oven, top with the mini marshmallows, and broil for up to 30 seconds, 6-8 inches from the top broiler until the marshmallows are melty and lightly golden. Let cool slightly before serving.