Ingredients:

2 medium sweet potatoes

1 1/2 cups flour

1 teaspoon cinnamon

3/4 teaspoon ginger

1/4 teaspoon nutmeg

1/2 teaspoon baking powder

1/2 teaspoon baking soda

1/4 teaspoon salt

1 cup sugar

1/2 cup vegetable oil

2 large eggs

1 teaspoon vanilla extract

Directions: 

Preheat oven to 400 degrees. Pierce sweet potatoes with a fork and wrap in tin foil. Roast for 40-50 minutes or until soft. Let cool.

Cut potatoes in half and scoop out flesh. Place in a food processor fitted with a blade and pulse until smooth.

In a medium bowl, sift together flour, cinnamon, ginger, nutmeg, baking soda, baking powder and salt.

Add pureed sweet potatoes, sugar and oil to a large bowl. Beat on medium-high speed with an electric mixer until smooth. Add eggs one at a time beating well after each addition. Add vanilla. Add flour mixture in batches; beat just until blended.

Preheat oven to 325 degrees. Line and grease muffin tins. Fill muffin trays until 3/4 full.

Bake for 20 to 25 minutes or until a toothpick inserted comes out cool. Allow to cool.

Make frosting (see recipe below).

Pipe frosting in a swirl on top of each cupcake. Using a hand-held blow torch, gently drag the torch across the frosting, toasting the frosting until just lightly brown.

Yield: 12 cupcakes

Marshmallow Frosting (half recipe) 

(via Jennifer Shea of Trophy Cupcakes)

Ingredients:

8 large egg whites

2 cups sugar

1/2 teaspoon cream of tartar

2 teaspoons pure vanilla extract

Directions:

Place egg whites, sugar, and cream of tartar in the heatproof bowl of an electric mixer. Set over a saucepan with simmering water. Whisk constantly until sugar is dissolved and whites are warm to the touch, 3 to 4 minutes.

Transfer bowl to electric mixer fitted with the whisk attachment, and beat, starting on low speed, gradually increasing to high, until stiff, glossy peaks form, 5 to 7 minutes. Add vanilla, and mix until combined. Use immediately. 

Yield: enough for 2 dozen cupcakes