Via whisk-kid.com
The Process – {Sweet Potato Ginger Spice Cake with Toasted Marshmallow Filling and Brown Sugar Maple Buttercream}
Autumn Delight Cake slightly adapted from Sweetapolita
I know it’s no longer autumn, but we’ve been enjoying a mild winter for a number of weeks, so I’m keeping the autumn spirit alive with this cake. It’s a combination of dense, fluffy and smooth that I’m sure you’ll love. The toasted marshmallow filling is my favorite component!
Sweet Potato Ginger Cake
2 lbs (908 g) sweet potatoes (about 3 large)
2 c (230 g) cake flour
2 tsp baking powder
1 tsp salt
1 Tbsp cinnamon
1 tsp ground nutmeg
1/2 tsp powdered ginger
2 c (400 g) sugar
4 eggs, room temp
1 1/4 c (315 ml) sunflower oil (or vegetable, safflower, canola oil)
2 tsp vanilla
2 Tbsp brandy or dark rum
3/4 c (120 g) crystallized ginger chips
Preheat oven to 350F. Oil and line two 8″ cake pans and set aside.
Place the sweet potatoes on a microwave-safe plate and pierce them with a fork. Microwave until they are tender throughout, about 7-8 minutes per side, and allow to cool. When they are cool enough to handle, remove the skin and mash into a coarse puree. Set aside.
In a medium size bowl, whisk together the flour, baking powder, salt, cinnamon, nutmeg and ginger. Set aside.
Combine the eggs and sugar in the bowl of your mixer and beat together with the paddle attachment until light and fluffy, about 5 minutes. Add the oil and beat to incorporate. Add the cooled sweet potato puree, vanilla and rum, then mix until well combined.
Sift the mixed dry ingredients over the batter in one addition and mix gently to combine, scraping the sides of the bowl. Fold in the crystallized ginger chips.
Divide the batter between the two prepared pans and smooth the tops with an offset spatula. Bake until the top springs back when gently pressed, about 40 minutes. Cool cakes in pans on a rack for ten minutes, then remove from pans and wrap in plastic wrap. Place in the fridge to cool completely.
Brown Sugar and Maple Swiss Meringue Buttercream
Please click here for a step-by-step guide to making Swiss Meringue Buttercream and troubleshooting tips!
5 egg whites
1 1/4 c (250 g) light brown sugar
1 1/2 c (340 g) butter, room temp and cut into cubes
2 tsp vanilla
2 Tbsp maple syrup
In a double boiler, cook the egg whites and sugar over medium heat, whisking constantly, until the sugar is completely dissolved and the mixture is hot, about five minutes (test by rubbing some between your fingers. If it’s completely smooth, it’s done). Pour into another bowl (a stand mixer is preferable) and whip on high speed until room temp. Then, on a medium-low speed, add the butter, waiting until each piece is completely incorporated before adding the next. The buttercream may turn into a soupy curdled mess during this process, but if you continue beating it for a few minutes it will become light and fluffy. Add the vanilla and maple syrup, then beat to combine.
Whipped Toasted Marshmallow Filling
This is best used immediately (but it keeps fine in the cake), and should be kept at room temperature until needed for assembly. Also, it tastes amazing. Try to save some for the cake 😉
12-16 standard-size marshmallows
1 c (227 g) butter, room temp
1 c (125 g) confectioner’s sugar, sifted
2 Tbsp milk
1 tsp vanilla
7.5 oz Marshmallow Fluff
pinch of salt
Turn on your broiler and arrange marshmallows on a cookie sheet lined with parchment paper. Place tray in lower rack of oven and broil until browned on top, keeping a close eye on them. Remove the tray and carefully flip the marshmallows. Return to the oven and broil until the other half is browned. Cool on a wire rack.
Whip the butter with the paddle attachment until very light and fluffy, about 8 minutes.
Add the confectioner’s sugar, milk, vanilla and salt and mix slowly to incorporate, then beat for another 6 minutes.
Add the cooled toasted marshmallows and marshmallow fluff, mixing on low speed for about 2 minutes.
Assembly
Click here for a tutorial for assembling layer cakes, and here for my preferred frosting method.
2 x 8″ Sweet Potato Ginger Cake
Whipped Toasted Marshmallow Filling
Brown Sugar Maple Swiss Meringue Buttercream
Remove the chilled Sweet Potato Ginger Cakes from the freezer and level them. Cut each in half horizontally.
Set one layer down on your serving plate and top with 1/3 of the Whipped Toasted Marshmallow Filling. Spread evenly from the center out to the edges. Place another layer on top, and add another third of the filling. Spread to the edges and repeat one more time. After placing the last layer of cake on top, crumb coat the entire cake with the Brown Sugar Maple Buttercream to seal in any stray crumbs. Frost as desired with remaining buttercream.