Sweet Potato Cupcakes with Toasted Marshmallow Frosting
These cupcakes are moist, fluffy and full of warm, fall spices. The toasty marshmallow frosting just takes these right over the top! A great fall treat! Recipe and more at The Alchemist
Sweet Potato Cupcakes with Toasted
Marshmallow Frosting
Makes about 24 cupcakes
An original recipe by me, Melissa aka The Alchemist
** Note** These cupcakes after being frosted need to be served the same day. This type of frosting doesn't keep well. Serving them within a 3-4 hours is best, so plan accordingly. The cupcakes, unfrosted can last longer, as I noted below in the recipe.
Also you may need to double the frosting recipe to get as much frosting as I have on each cupcake. But! You can only make one batch at a time, because that is how much frosting can fit in the bowl of a stand mixer. Just be prepared and know you may need to make a second batch. If you use less frosting this amount may be enough.
Ingredients for Cupcakes
32 oz. sweet potatoes or yams (to equal 2 cups (536 g.) mashed after cooking)
2 3/4 cups (377 g.) all purpose flour
4 tsp. ground cinnamon
2 tsp. ground ginger
1/4 tsp. ground cloves
1 tsp. ground allspice
1/2 tsp. freshly ground nutmeg
1 tsp. baking powder
1 tsp. baking soda
1/2 tsp. salt
1 cup (190 g.) white sugar
1 cup packed (185 g.) brown sugar
1 cup (237 ml) vegetable oil
1 cup (216 g.) yogurt - I used Greek yogurt, full fat or low fat is fine, don't use nonfat
4 eggs
3 tsp. vanilla extract
Ingredients for Frosting
10 large egg whites
2 cups (380 g.) white granulated sugar
1/2 tsp. cream of tartar - This helps with the stability and volume of meringue, if you don't have this, or can't find it, it's o.k. to leave it out, but I do recommend it, especially if you are new to making a meringue.
1/8 tsp. salt
2 tsp. vanilla extract
Directions for Cupcakes
First cook the sweet potatoes. You can do this step a day or up to 3 days in advance. Preheat the oven to 400 degrees Fahrenheit, 200 degrees Celsius, or Gas Mark 6. Wash and scrub the sweet potatoes and pierce them a few times with a fork or a knife. Bake them in the preheated oven until they are soft, about 1 hour. Alternately, you can cook them in the microwave. Wash them and pierce them, and cook them for 8-10 minutes or until tender, turning them over once during cooking. Let them cool, then peel and mash them to equal 2 cups mashed or 536 g.
Start on the cupcakes - Preheat the oven to 350 degrees Fahrenheit, 180 degrees Celsius, Gas Mark 4.
In a large bowl, whisk together the dry ingredients, the flour, cinnamon, ginger, cloves, allspice, nutmeg, baking powder, baking soda and salt. Set aside.
In the bowl of a stand mixer, or in another large bowl with a hand mixer, mix together the 2 cups of mashed sweet potatoes, the oil and the white sugar and brown sugar, beat it until smooth. Add the eggs, one at a time, beating in between each addition. Scrape down the bowl and add the vanilla and the yogurt and beat it until everything is incorporated. Add the dry ingredients and beat until it is mixed together well, without over beating.
Fill cupcake cups 2/3 - 3/4 of the way full. I used miniature panettone cups I bought at Sur La Table. Whatever type you use, the greaseless cupcake liners are best, since all of my recipes have a high liquid and high oil content, if you use regular cupcake papers they may be greasy or oily on the bottoms, if you use the greaseless kind, that becomes a non issue.
Bake for 22-28 minutes, or until a toothpick comes out clean.
Cool the cupcakes before frosting them.
Cupcakes can be stored unfrosted for 2 days in an airtight container in the fridge. Or freeze them by wrapping them in plastic wrap then placed in a ziptop bag that is airtight. They can be frozen for 6 months at least, if wrapped well.
Directions for Frosting
Place the broiler on your oven on high and arrange a rack in the middle of the oven. Or alternately, you can use a kitchen torch, if you are using a torch, obviously don't preheat your broiler.
Fill a medium saucepan with a few inches of water and bring to a simmer. The saucepan needs to be a size that hold the bowl of your stand mixer on top of it, like a double boiler. (I have this pictured above.) When it starts to boil turn it down to medium. Put the egg whites, sugar, cream of tartar and salt in a clean bowl (the bowl needs to be very clean, there can't be any bit of grease in it or your meringue won't work) of a stand mixer and whisk by hand to combine. Place the bowl over the saucepan (make sure the water doesn't touch the bowl) and cook, whisking constantly until the sugar has dissolved and it is hot to the touch (about 120 degrees Fahrenheit, 48 degrees Celsius) on an instant read thermometer, about 5 minutes.
Transfer the bowl to the stand mixer fitted with the whisk attachment. Beat on medium for 2 minutes then turn up the mixer to medium high and beat until stiff, glossy peaks form, about 5 minutes more. You need to beat it on medium first, if you were to just beat it on high for the entire time the meringue can become dry, so it's best to gradually bring it up to the medium high speed and not just beat it on high the entire time. Add the vanilla and whisk until it's incorporated.
Transfer the frosting to a piping bag fitted with a large star tip. Pipe the frosting on the cupcakes.
Broil the tops to make them toasted. If using a kitchen torch, torch the tops until they are slightly brown and toasted. If using the oven, place the frosted cupcakes onto a cookie sheet or jelly roll pan. Place it on the middle rack of the oven. Broil them for 20-30 seconds, or just until they get brown and toasty. *** THIS IS IMPORTANT*** These can go from being done to burnt in what seems like a second. so don't walk away. Just stand there, even if you hold open the door to the oven slightly, to see what's going on, or you can set a timer for 20 seconds, then check them and see if they are toasted. Toast them until the tops are toasted lightly. It's better to keep checking them, than having them burn and have to start over.
Serve them within 3-4 hours of making them. If you must store a few cupcakes overnight, do so at room temperature in an airtight container. The trouble with storing them is, if you trap a moist cupcake in an airtight environment it's going to make the meringue which needs to be kept dry, wet. So overnight or the next day, the meringue will start to "sweat" or weep, get moist and start to fall off the cupcakes. Or if you were to keep them out in the open with air circulation, the cupcakes will dry out.