Peel sweet potatoes and cut into 1” cubes. Bring a large pot of salted water to a boil. Drop in the sweet potato cubes, reduce heat, and simmer 12 to 15 minutes until tender enough to easily puncture with a fork. Drain sweet potatoes and mash until smooth. Let cool.
1-2 sweet potatoes
Prepare a 9" cake pan (see notes). Preheat oven to 350℉.
In a large mixing bowl, beat butter and sugar until fluffy.
2 sticks butter, 1 cup brown sugar
Add egg and beat until incorporated.
2 eggs
Beat in cooled sweet potatoes.
Add in the vanilla and mix.
1 tablespoon vanilla
Add the flour, cornstarch, baking soda, baking powder, and salt and mix until just incorporated.
1 cup flour, ¼ cup cornstarch, 1 teaspoon baking soda, 1 teaspoon baking powder, 1 teaspoon kosher salt
Spread into prepared cake pan and bake for 50-60 minutes. Cool in the cake pan for about 5 minutes then flip out onto a wire rack to cool completely.
Marshmallow Frosting
Cream butter until fluffy. Add the rest of the frosting ingredients and beat until well combined.
2 sticks butter, 3 cups powdered sugar, 2 tablespoons bourbon, 2 tablespoons maple syrup, 1 ½ cups Marshmallow Fluff
Spread onto cooled cake, slice, and enjoy!
Notes
To easily line a cake pan, spray the bottom and sides of the pan with nonstick spray. Cut a circle out of parchment paper, place in the bottom of the pan, and then spray the parchment with nonstick sprayThis cake can be made as a two layer cake by dividing the batter between two cake pans and reducing the bake time to 35-45 minutes. Once the cakes have cooled, spread the marshmallow frosting between the layers and on top of the top layer.An 8x8 baking pan can be used in place of a 9" round cake pan. For cupcakes, reduce bake time to 18-24 minutes, and for mini cupcakes, reduce bake time to 10-15 minutes.