Dolly Parton makes her sweet potato casserole with a nutty twist.Ingredients for Dolly Parton's sweet potato casserole. Anneta Konstantinides/Business Insider To make Parton and her sister's sweet potato casserole at home, you'll need:5 large sweet potatoes, peeled and quartered2 cups miniature marshmallows cup chopped raw pecans cup light brown sugar, packed cup (1 stick) butter at room temperature, plus more for greasing1 teaspoon vanilla extract1 teaspoon salt1 teaspoon ground cinnamon First, I preheated the oven and prepped my potatoes and baking pan.I quartered my sweet potatoes after peeling them. Anneta Konstantinides/Business Insider I set the oven to 350 degrees Fahrenheit and buttered a 9-inch by 13-inch pan, per Parton's instructions.I also washed, peeled, and quartered my sweet potatoes. I placed my sweet potatoes in a large pot and covered them with cold water.I cooked the potatoes for 20 minutes. Anneta Konstantinides/Business Insider I brought the pot to a boil over high heat, then lowered the heat to maintain a low boil for 20 minutes while the potatoes cooked.Parton said you'll know the potatoes are ready when they're "fork tender."I drained the potatoes, placed them in a large bowl, and added the butter and seasonings.Seasoning my sweet potatoes. Anneta Konstantinides/Business Insider I threw in the brown sugar, vanilla, salt, cinnamon, and butter, adding the latter in knobs so it'd be easy to mix. Then, it was time to mash.My mashed sweet potatoes. Anneta Konstantinides/Business Insider Parton recommends using a potato masher to mix the ingredients until they're "well combined," but I don't own one, so I simply used a big wooden fork. It worked like a charm.I transferred my mashed sweet potatoes to the baking pan, smoothing the top.I covered the top of the pan with marshmallows, as Dolly instructed. Anneta Konstantinides/Business Insider I sprinkled the pecans before evenly covering the casserole with my miniature marshmallows. I covered my pan with aluminum foil and threw it in the oven.My covered pan. Anneta Konstantinides/Business Insider Parton says you should bake your sweet potato casserole for 20 minutes.Once the 20 minutes were up, I removed the foil and baked the sweet potato casserole for five more minutes.My sweet potato casserole after 20 minutes in the oven. Anneta Konstantinides/Business Insider Parton says your marshmallows should be "golden brown" once the five minutes are up. My marshmallows were still white as snow, so I turned on the broiler and baked the casserole for two additional minutes to give them some color. I let my sweet potato casserole cool for 15 minutes before serving, per Parton's recommendation. Then, everyone dug in!I would make Dolly Parton's sweet potato casserole again, with one little tweak. Anneta Konstantinides/Business Insider I was slightly disappointed when the sweet potato casserole came out of the oven. The marshmallows got a little overcooked by the broiler and now only covered half of the casserole. Next time, I think I'll skip Parton's aluminum foil trick and just let the marshmallows cook uncovered the entire time.But unphotogenic marshmallows aside, the flavor of this sweet potato casserole was delicious. The crunch of the pecans was a delightful twist, and the combination of the brown sugar, vanilla, and cinnamon was well-balanced. The texture was satisfyingly creamy, and the dish smelled delicious. I brought this for a recent Friendsgiving, and the pan was empty within minutes despite having a lot of competition!So, with one little tweak, I think the Parton sisters' sweet potato casserole will be a hit on your holiday menu.