Sweet Potato Cupcakes with Toasted Marshmallows and Candied Pecans

 

  

I was set on the idea of bringing fall-festive mini-cupcakes to a Halloween party this year, and I found this recipe for Candied Sweet Potato Cupcakes in Martha Stewart's Cupcakes book. I'd never seen a cupcake topped with toasted marshmallows (such a great idea!) so I absolutely had to try it. It's like the cupcake version of the Thanksgiving classic (well, in the Midwest at least) of mashed sweet potatoes topped with marshmallows. The cupcakes turned out well, despite their many steps from beginning to end. But one could simplify this recipe by not making it completely from scratch (purchase frosting and candied nuts, for example). But that's not my style, so I went all the way. Roasted the potatoes, made the cakes, made the butter cream, toasted the marshmallows, candied the nuts... but it was all worth it in the end. The flavor of the sweet potatoes comes through, and makes the cake a little more dense which stands up nicely to the delicate marshmallow topping. The nuts don't add much to the taste, but they do add a nice crunch if you choose to add them. And really, in the end, you can't beat how cute those little piles of toasted marshmallows look! 

I modified Martha Stewart's recipe slightly, by adding some buttercream "glue" underneath the marshmallows.

RECIPE:
Sweet Potato Cupcakes with Toasted Marshmallows and Candied Pecans
from Martha Stewart's "Cupcakes"
makes 24 regular-sized cupcakes or about 50 miniature cupcakes 

INGREDIENTS:
Cake:
2 pounds (about 3 medium) sweet potatoes, scrubbed
2 cups all-purpose flour
2 teaspoons baking powder
2 teaspoon salt
2 teaspoons cinnamon
1/2 teaspoon nutmeg
1 cup (2 sticks) butter, room temperature
2 cup granulated sugar
1 cup brown sugar
4 eggs, room temperature
2 teaspoons vanilla extract

Frosting:
Swiss Meringue Buttercream (see below) or other white frosting

Topping:
2-3 cups miniature marshmallows
Candied Pecans (see below)

DIRECTIONS:
Roasting Sweet Potatoes:
Preheat oven to 400F. Pierce sweet potatoes with a fork and place on a parchment-lined rimmed baking sheet. Bake until completely soft and juices begin to seep from the potatoes and caramelize, about 1 hour. Remove from oven.When cool enough to handle, slice potatoes in half lengthwise and use a fork to scrape the flesh from the skin into a bowl, discarding the skins. Mash potato with a fork until smooth. You should have about 2 cups. This can be done several days in advance; store mashed sweet potatoes in an air-tight container in the refrigerator.

Cake:
Preheat oven to 325F. Line muffin tins with paper liners. Whisk together flour, baking powder, salt , cinnamon, and nutmeg. With an electric mixer on medium-high speed, cream butter and both sugars until pale and fluffy. Add eggs, one at a time, beating until each is incorporated, scraping down sides of bowl as needed. Beat in mashed sweet potatoes and vanilla. Reduce speed to low. Add flour mixture in three batches, beating until completely incorporated after each addition.

Divide batter evenly among lined cups, filling each three-quarters full. Bake until cupcakes are set and a cake tester inserted in centers comes out clean, about 15 minutes for mini-cupcakes or 28 minutes for regular cupcakes. Transfer tins to wire racks to cool completely before removing cupcakes. Cupcakes can be stored up to 3 days at room temperature, or frozen up to 3 months in airtight containers.

Topping:
Make (or purchase) your frosting of choice, and put a nice dab on each cupcake. It's up to you how generous you want to be here.

Divide marshmallows evenly into mounds (or, use about 5 marshmallows for each mini-cupcake), and place marshmallow piles on a large baking sheet or nonstick baking mat. Using a small kitchen torch, brown marshmallows all over (or heat under the broiler, watch the whole time -- it takes about 1 minute to toast the marshmallows). With an offset spatula, transfer mounds to cupcakes, and press marshmallows lightly into frosting to stay in place. Top with candied pecans, dividing evenly. Cupcakes are best served the day they are topped; keep at room temperature.

* * *

Swiss Meringue Buttercream:
This is my go-to frosting for a great, rich-tasting, reliable buttercream. The process is more involved than your standard powdered sugar and butter, but the result is worth it.
INGREDIENTS:
1/2 cup egg whites
1 cup granulated sugar
12 ounces (3 sticks) butter, room temperature and cut into tablespoon-sized pieces

Combine the egg whites and sugar in the bowl of a mixer, but remove the bowl from the mixer and rest it over a saucepan with about an inch of simmering water. Whisk the mixture together until all the sugar has dissolved (if you rub the mixture between your fingertips, it should feel completely smooth with no grains of sugar). Put the bowl back onto the mixer, and whip the egg whites and sugar with a whisk attachment on medium speed until the mixing bowl has cooled and the mixture has formed a meringue, about 5-10 minutes. Change the whisk attachment to a paddle attachment and with the mixer on medium-low speed, add the butter in 6 additions, about 10 seconds apart. Change the speed to medium and beat until the mixture has formed a smooth consistency, about 10 minutes. After all the butter has incorporated into the meringue, the mixture will start to look more and more curdled. LET THIS HAPPEN! The mixture will turn lumpy and curdled looking, and then it will come back to a creamy state. It needs to go through this transition to yield the rich, smooth buttercream that you're going for.

(Can be refrigerated for 3 days, or frozen for up to a month; before using, bring to room temperature and beat with a paddle attachment on low speed until smooth)

Simple White Frosting:
1.5 cups (3 sticks) butter, room temperature
1 pound (4 cups) powdered sugar, sifted
1/2 teaspoon vanilla extract

With an electric mixer, beat butter on medium-high speed until pale and creamy, about 2 minutes. Reduce speed to medium. Add powdered sugar, 1/2 cup at a time, beating well after each addition. After every two additions, turn mixer speed to high and beat for 10 seconds, then return to medium. Frosting should be very pale and fluffy. Add vanilla extract and beat until smooth.

(Can be refrigerated for 10 days; before using, bring to room temperature and beat on low speed until smooth)

Candied Pecans:
1/2 cup sugar
1/4 cup water
1 cup coarsely chopped pecans

Line a rimmed baking sheet with a nonstick baking mat. Heat sugar and water to a simmer in a heavy saucepan over medium heat, stirring occasionally, until sugar is dissolved. Stop stirring; cook until syrup comes to a boil, washing down sides of pan with a wet pastry brush to prevent crystals from forming. Boil, gently swirling pan occasionally, until mixture is a light amber. Remove from heat. Stir in pecans with a wooden spoon to coat completely. Immediately remove pecans from caramel; spread in a single layer on prepared baking sheet. Let cool completely before using or storing; break into small pieces, if necessary.