Mashed Sweet Potato Casserole with Marshmallow Meringue
A grown-up version of the classic sweet potato side dish that cuts down the sweetness by using a homemade marshmallow like topping. No more sickeningly sweet marshmallows from a bag, instead you get a light and airy meringue like topping that compliments the sweet potatoes. Grab a kitchen torch for a beautiful s'more like topping.
Wash and dry the sweet potatoes, then poke holes across the tops of each one with a fork. Place sweet potatoes in the microwave and cook on high for 4-8 minutes, until soft. Allow to cool slightly, then remove the peelings. Add the sweet potato flesh to a large bowl and mash with a potato masher, or run through a potato ricer.
Add the evaporated milk, sugar, vanilla extract, and melted butter to the mashed sweet potatoes and mix with a hand mixer until well combined. Pour into a 9 x 13 or 2 quart baking dish. Bake uncovered for 25-30 minutes until the edges are bubbly.
Fill a medium saucepan with water and heat over medium heat until simmering.
In the bowl of a stand mixer, whisk together the egg whites, cream of tartar, and sugar. Place the bowl over simmering water and whisk by hand for about 4 minutes, until the sugar has dissolved and the mixture is warm to the touch but not hot.
Remove from the heat and set the topping back on the stand mixer. With the whisk attachment, beat on high for 5-7 minutes until you have very stiff glossy peaks. Add vanilla and mix again for a few seconds, then spread the topping over the hot casserole.
Use a kitchen torch to toast the topping, or you can place under the broiler for about 1 minute. Watch it very carefully as it can easily burn.
Serve hot.
Barbara's Notes + Tips
If needed, cook the sweet potatoes in batches so they cook more evenly. It’s also helpful if you choose sweet potatoes that are similar in size so they cook in about the same amount of time.
To get a thick topping make sure that no egg yolks get mixed with the whites.
Don't let the toppoing get hot, it should be just warm enough for the sugar to melt
Swirl the meringue topping with a spatula to make pretty swirls.
If broiling the topping, leave the door of the oven open a little so that you can watch it. It will turn brown quickly.