Sweet Potato Sheet Cake with Marshmallow Frosting
Sweet Potato Sheet Cake with Marshmallow Frosting is a moist, spiced dessert that perfectly balances the natural earthiness of sweet potatoes with a fluffy, creamy marshmallow topping. Ideal for holidays, family dinners, or casual gatherings, this cake offers a unique flavor fusion, tender crumb, and luscious frosting that everyone will love.
- Prep Time: 20 minutes
- Cook Time: 35 minutes
- Total Time: 55 minutes
- Yield: 12 servings 1x
- Category: Dessert
- Method: Baking
- Cuisine: American
- Diet: Gluten Free (if using gluten-free flour)
Ingredients
Scale
Cake Ingredients
- 2 cups cooked and mashed sweet potatoes
- 2 ½ cups all-purpose flour
- 1 ½ cups granulated sugar
- 1 cup unsalted butter, softened
- 3 large eggs
- 1 teaspoon baking soda
- 1 teaspoon baking powder
- 1 teaspoon ground cinnamon
- ½ teaspoon ground nutmeg
- ½ teaspoon salt
- 1 cup milk or buttermilk
- 1 teaspoon vanilla extract
Marshmallow Frosting
- 1 ½ cups marshmallow fluff
- ½ cup unsalted butter, softened
Instructions
- Prepare the Sweet Potatoes: Start by boiling or baking peeled sweet potatoes until tender. Once soft, mash them until smooth and set aside to cool. This will be the moist base that infuses the cake with its beautiful flavor.
- Mix the Dry Ingredients: In a large bowl, whisk together the flour, baking soda, baking powder, cinnamon, nutmeg, and salt. Combining these ingredients early ensures even distribution of spices and lift throughout your cake.
- Cream Butter and Sugar: In a separate bowl, cream the softened butter with sugar until light and fluffy. This step adds airiness, aiding the cake’s tender crumb and depth of sweetness.
- Add Eggs, Vanilla, and Milk: Beat in the eggs one at a time, followed by vanilla extract. Alternate adding the dry mixture and milk, beginning and ending with the dry ingredients. This method prevents overmixing while keeping the batter smooth.
- Incorporate the Sweet Potatoes: Fold in the mashed sweet potatoes gently to maintain a fluffy texture but incorporate the moisture evenly.
- Bake the Cake: Pour the batter into a greased sheet pan and bake in a preheated oven at 350°F (175°C) for about 30-35 minutes or until a toothpick inserted in the center comes out clean. The cake will rise with a golden-brown top and soft interior.
- Prepare the Marshmallow Frosting: While the cake cools slightly, prepare your marshmallow frosting by whipping marshmallow fluff with softened butter until smooth. Spread it generously over the warm cake for a luscious, creamy top layer.
Notes
- Use fresh sweet potatoes for the best flavor and moistness, avoiding canned alternatives.
- Don’t overmix the batter to keep the cake light and tender.
- Adjust baking time as ovens vary; begin checking at 30 minutes.
- Allow the cake to cool until just warm before frosting to prevent melting.
- Store leftovers in an airtight container at room temperature for up to 3 days or refrigerate for up to 5 days.
- For gluten-free, substitute all-purpose flour with a 1-to-1 gluten-free baking blend containing xanthan gum.
- Variations include vegan substitutions, nut add-ins, extra spices, and citrus zest for different flavor profiles.
Nutrition
- Serving Size: 1 slice (1/12 of cake)
- Calories: 350 kcal
- Sugar: 28 g
- Sodium: 150 mg
- Fat: 18 g
- Saturated Fat: 10 g
- Unsaturated Fat: 6 g
- Trans Fat: 0 g
- Carbohydrates: 42 g
- Fiber: 3 g
- Protein: 4 g
- Cholesterol: 60 mg
Keywords: sweet potato sheet cake, marshmallow frosting, moist cake, spiced cake, holiday dessert, gluten-free cake, autumn dessert