This Sweet Potato Cake has a delicious icing made with marshmallow fluff! It's a true taste of home! No one will know it started with a simple muffin mix!
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Mama's Sweet Potato Cake with Marshmallow Buttercream Frosting

Prep Time20 mins
Cook Time35 mins
Total Time55 mins
Servings: 9 to 12


For Cake

  • 2 packets Martha White Sweet Potato Muffin Mix
  • 1 tbsp. ground cinnamon
  • ½ tsp. salt
  • 1 cup milk
  • 1 cup sour cream
  • ½ cup chopped pecans

For Frosting

  • 1 cup butter salted or unsalted, softened to room temp.
  • 1 (7.5 oz.) jar marshmallow creme (Marshmallow Fluff)
  • 1 cup powdered confectioners sugar
  • ½ tsp. vanilla extract
  • ½ cup chopped pecans for topping
  • cup Smucker’s Salted Caramel Topping


For Cake:

  • Preheat oven to 350F degrees. Spray a 9x9 baking dish with non-stick cooking spray.
  • In a medium bowl, combine two packets sweet potato muffin mix with ground cinnamon and salt. Stir well.
  • Then stir in milk and sour cream. Once combined, gently stir in chopped pecans.
  • Pour batter into prepared baking dish.
  • Bake for 30-35 minutes until an inserted toothpick comes out clean.
  • Allow cake to cool completely before making frosting.

For Frosting:

  • Using an electric mixer, beat butter in a medium bowl on high speed until creamy.
  • Add in marshmallow creme and mix well.
  • Reduce mixing speed to low and beat in confectioners sugar and vanilla.
  • Increase mixing speed to high and beat until fluffy.
  • Spread frosting onto cooled cake. Sprinkle top with chopped pecans. Then, using a spoon, drizzle salted caramel over the finished cake. Depnding on how large the slices, you should be able to get 9-12 slices of ckae from this recipe.


Once cake is cooled, you may invert cake onto a large plate and then frost. This makes it a bit easier to slice and serve the cake. For a thinner cake, use a 9x13 pan and adjust baking time accordingly.