This sweet potato casserole recipe goes great alongside meals as low-key as chicken dinners or as high volume as festive holiday banquets. If you\u2019re cooking this for a crowd, you can make everything but the streusel a day ahead so you won\u2019t have to break a sweat in front of your guests.\r\n\r\n\n\n\tHow To Make Copycat Boston Market\u2019s Sweet Potato Casserole\n\t\t\n\t\t\t\n\t\n\t\tSweet Potatoes3 \u00bd lb sweet potatoes (up to 4 lb; peeled and cut into 1\u201d pieces)24 tbsp butter (or 1\/2 stick)\u00be light brown sugar\u00bd cup heavy cream1 tsp kosher salt1 tbsp vanilla extract1 tsp ground cinnamon\u00bc tsp ground nutmegStreusel Topping2 cups mini marshmallows4 tbsp unsalted butter\u00bd cup all-purpose flour6 tbsp light brown sugar\u00bc cup old fashioned rolled oats\u00bc tsp ground cinnamon\t\n\t\n\t\tBoil the potatoes in a large pot over high heat, until fork tender.Drain potatoes and place back in the pot. Mash or blend until smooth.Add the rest of the ingredients for sweet potatoes and mix until fully combined.Preheat oven to 350\u00b0F. Grease a casserole dish.Spoon sweet potatoes into dish and smooth out.Sprinkle with marshmallows on top.Melt butter in a saucepan, add remaining topping ingredients and mix.Pour on top of sweet potato and marshmallows.Bake for 20-25 min until streusel is crisp and marshmallows are golden brown. Serve.