Purple Sweet Potato Cake Recipe with Marshmallow Cream Cheese Frosting
This deliciously decadent and technically accurate Purple Sweet Potato Cake with Marshmallow Cream Cheese Frosting is so good, it is impossible to resist!

- Prep time
- 20 min
- Cook time
- 40 min
- Yield
- 15 servings
- Difficulty
- HARD
Ingredients
Quantities are shown as originally provided.
- 2 ¾ cups all purpose flour
- 1 ½ cups sugar
- 2 tsp baking powder
- 1 tsp baking soda
- 1 cup cooked mashed purple sweet potato ((please read text for specification))
- 1 cup milk
- ¾ cup sour cream
- 1⁄3 cup canola oil
- 2 tsp vanilla extract
- ½ tsp salt
- few drops purple food coloring ((optional))
- 8 ounces cream cheese
- 8 ounces butter ((2 sticks))
- 7 ounces marshmallow fluff
Instructions
- 1
Grease and flour two 8 inch cake pans and set aside.
- 2
Preheat your oven to 350°F or 180°C
- 3
Combine the flour, baking powder and baking soda and salt with a whisk and set aside.
- 4
Using a stick blender or in a blender, blend the mashed potatoes, milk sour cream canola oil, sugar, and vanilla extract until it is smooth and properly incorporated. Don't try to do this step with just a whisk, it will not mix evenly, and it is important that it does. If you want a more vibrant cake, add a few drops of purple food coloring, otherwise, skip it.
- 5
Combine the wet and the dry ingredients with a whisk until there are no lumps in the batter, and the cake is evenly mixed. Do not over mix!
- 6
Split the cake mixture into the two prepared 8 inch cake pans, and bake in the preheated oven for 35-40 minutes or until a skewer inserted in the middle of the pan comes out clean.
- 7
Allow to cool completely before frosting
- 8
Mix the cream cheese, butter, and marshmallow fluff in a mixer or with a hand mixer until it is well combined.
- 9
Store in the refrigerator until ready to use.
- 10
Simply assemble the cake as neatly or as rustic as you wish and decorate with leftover mashed potato pieces and toasted crushed walnuts.