Sweet Potato Cake with Marshmallow Meringue

Sweet Potato Cake with Marshmallow Meringue is a pillowy soft slice of heaven. Perfectly seasoned with your favorite fall spices, this sheet cake is topped with a thick layer of homemade marshmallow frosting.

I know what I see when I see it. Forget that my chiropractor reads MRI’s for a living and I’ve never laid eyes on one until today. There’s no way the neck abnormalities she’s pointing out are herniated discs. With all due respect to her specialized training (and all due disclaimers that my experience reading magnetic resonance imaging is diddly squat) I don’t see disc displacement, I see dessert lodging.

If you never heard of dessert lodging it’s because I just made it up. It’s a self-inflicted condition caused by scarfing down sweet potato cake so fast that you forget to chew. Of course, my chiropractor now thinks I need my head examined more than my spine, but yours truly can spot a dessert a mile away. And in a close proximity MRI scan. Contrary to my diagnosis, I do not have bulging lumbar in my neck, I have globs of marshmallow frosting.

Lesson learned: when you swallow cake whole, you pay a price–$250 to be exact. I’d like to say it was money well spent but if you’ve ever been shoved in an MRI machine, you know that’s a lie. It’s like a 20-minute test drive for the crematorium oven only you’re not dead, you just wish you were. Ironically, it was an oven that got me in this predicament in the first place. I baked a sweet potato cake and it tasted so amazing that it gave me tingles up and down my limbs.

My buzz-kill doctor said the tingling was actually nerve damage then, speaking of nerve, asked me if I understood what she was saying like I rode the short bus to my appointment. Now we both understand that I’m not sharing any cake with her. From here on out, the doc is entitled to her professional opinion, but not to any toasted marshmallow frosting. The more the merrier for me, I say. I literally get to have my cake and eat it, too. It’s just that I have to eat it while strapped in a spinal decompression chair.

Before sharing the recipe for Sweet Potato Cake, here are a few baking tips to help you out:

Ingredient Tips

To bake your sweet potatoes before mashing, pierce potatoes all over with a fork then bake at 400 degrees for 45 minutes or until tender. After cooling, scoop out flesh and mash until smooth.

Always use the spoon and level method to measure flour. Scooping from the bag overpacks flour into the measuring cup which steals moisture from the cake like a thief.

Eggs need to be at room temperature before beginning. If you’ve forgotten to take yours out of the refrigerator ahead of time then speed up the process by placing it in a bowl of warm water. Don’t use hot water; we want to warm the eggs, not hatch them.

Preparation Tips

Sweet Potato Cake cake can be made 2 days in advance. Cover the cooled, unfrosted cake in plastic wrap then store in the refrigerator until ready to frost and serve.

Cool cake completely before adding marshmallow frosting.

How to Store Sweet Potato Cake

Marshmallow meringue will wilt when left at room temperature so it’s important to cover and store in the refrigerator. When frosted, this sheet cake will keep up to 2 days. Unfrosted sweet potato cake will keep up to 5 days.

Can you freeze Sweet Potato Cake? Yes, but only if it has not been frosted. Freezing marshmallow frosting is not recommended but the unfrosted cake can be frozen up to 3 months. For best results, double wrap cake, first in plastic wrap then in aluminum foil, before placing in an airtight container in the freezer.

I hope you enjoy this Sweet Potato Cake recipe. Please leave a rating and review below when you try it yourself. And, while you’re at it, sign up for my weekly Recipe Newsletter so you never miss a tempting recipe.

Finally, if you’re looking for more fall dessert recipes then check out these homemade Pumpkin Donuts. Topped with a coffee glaze, these soft, fluffy donuts are oven baked and spiced to perfection.

Sweet Potato Cake with Marshmallow Meringue

Heather Wolf

Sweet Potato Cake with Marshmallow Meringue is a pillowy soft slice of heaven. Perfectly seasoned with your favorite fall spices, this sheet cake is topped with a thick layer of homemade marshmallow frosting.

5 from 11 votes

Print Recipe Pin Recipe

Prep Time 45 minutes mins

Cook Time 30 minutes mins

Marshmallow Meringue 25 minutes mins

Total Time 1 hour hr 40 minutes mins

Course Cakes and Cupcakes

Cuisine American

Servings 12

Ingredients

  

Sweet Potato Sheet Cake

• 2 cups all-purpose flour unbleached
• 2 tsp baking powder
• 1 tsp baking soda
• 3 tsp cinnamon
• 1 tsp ginger
• 1/2 tsp nutmeg
• 3/4 tsp sea salt fine
• 1 cup unsalted butter softened to room temperature
• 1 cup dark brown sugar packed
• 1/2 cup granulated sugar
• 4 large eggs room temperature
• 2 cups mashed sweet potatoes room temperature
• 2 tsp vanilla extract pure

Marshmallow Meringue

• 6 large egg whites
• 1 1/2 cups granulated sugar
• 3/4 tsp cream of tartar
• 1 1/2 tsp vanilla extract pure
• 1/8 tsp sea salt fine

Instructions

 

Sweet Potato Sheet Cake

• Preheat oven to 350 degrees. Grease and flour the bottom and sides of a 9 x 13 baking pan.
• In a large mixing bowl, whisk together flour, baking powder, baking soda, cinnamon, ginger, nutmeg and salt. Set aside.
• In a separate bowl, use and electric mixer to beat butter and both sugars until creamy smooth – approximately 2 to 3 minutes.
• Add eggs, one at a time, beating after each addition until incorporated. Scrape down the sides of the bowl with a spatula as needed.
• Beat in sweet potatoes and vanilla extract until smooth and lump free.
• Reduce mixer speed to low. Add dry ingredients to wet, beating until just combined. Take care to not overmix.
• Pour batter into baking pan then smooth the top with a spatula.
• Bake for 30 to 35 minutes or until a tester inserted into the center comes out with a few moist crumbs. Avoid overbaking.
• Remove pan from oven and place on a baking rack to cool completely before frosting.

Marshmallow Meringue

• Using a double boiler, bring an inch or two of water to a simmer. Continuously whisk egg whites and sugar over heat until sugar has completely dissolved, approximately 7 minutes.
• Immediately transfer marshmallow meringue to a clean mixing bowl and beat with an electric mixer until soft peaks form, approximately 5 minutes.
• Add cream of tarter, vanilla and salt and continue beating until stiff peaks form, approximately 10 to 12 minutes.
• Spread frosting onto cooled cake.

  *Note: this recipe makes a thick layer of meringue. If you prefer a thinner layer of frosting, cut the recipe in half.
• Toast marshmallow meringue with a blow torch until golden brown (or under an oven broiler for 1 to 2 minutes) until golden brown.
• Place cake in the refrigerator to chill until frosting sets then slice and serve.
• Note: Frosting will begin to wilt if left at room temperature. To prevent wilting, cover and chill cake in the refrigerator up to 2 days.

Keyword cake, marshmallow, meringue, sweet potato