Sweet Potato Cake

If carrot cake and spice cake had a very cozy baby, it would be sweet potato cake. It bakes up deeply moist with a gentle sweetness and warm spices, and it stays tender for days. This is the kind of cake I make when I want something special without needing a bakery-level project.

My version uses mashed cooked sweet potato (not sweet potato pie filling), plenty of cinnamon and vanilla, and a thick layer of tangy cream cheese frosting that balances everything out.

Why you'll love this cake

• Moist for days: Sweet potato adds richness and keeps the crumb soft.
• Big flavor with basic ingredients: Pantry spices do a lot of heavy lifting.
• Flexible: Sheet cake, layer cake, cupcakes, or Bundt all work with small tweaks.
• Not fussy: No separating eggs, no syrup soaks, no complicated steps.

Ingredients (and why they matter)

Here is what you need for a classic sweet potato cake with cream cheese frosting. I am including notes because knowing the “why” makes baking feel way less mysterious.

For the cake

• Mashed cooked sweet potato: Use plain cooked sweet potato that you mash smooth. It adds moisture, color, and a mellow sweetness.
• All-purpose flour: Keeps it sturdy but still tender.
• Baking powder + baking soda: A combination gives lift and a soft, even crumb.
• Ground cinnamon: The main warm spice here.
• Ginger and nutmeg (optional but lovely): Adds that fall bakery aroma.
• Brown sugar + granulated sugar: Brown sugar brings caramel notes; white sugar keeps the cake light.
• Neutral oil: Oil tends to keep cakes moist longer than butter because it stays liquid at room temperature. Use canola, vegetable, or avocado oil.
• Eggs: Structure and richness.
• Vanilla + salt: Makes everything taste more like itself.
• Buttermilk (or quick sour milk substitute): Tenderizes and helps the cake rise nicely. To make a quick substitute, mix 1 cup milk with 1 tablespoon lemon juice or white vinegar and let it sit 5 minutes.

For the frosting

• Cream cheese: Full fat is best for a thick, stable frosting.
• Butter: Adds body and smoothness.
• Powdered sugar: Sweetens and thickens.
• Vanilla + pinch of salt: Keeps it from tasting one-note sweet.

How to cook sweet potatoes

You have a few good options. The goal is a soft sweet potato with most of the excess moisture cooked off, so your cake is fluffy instead of heavy.

• Roast (my favorite): Poke whole sweet potatoes with a fork and roast at 400°F until very tender, 45 to 70 minutes depending on size. Cool, scoop, mash.
• Microwave (fastest): Poke, microwave in 1 to 2 minute bursts until soft, usually 6 to 10 minutes total. Let steam off, then scoop and mash.
• Boil (works, but drain well): Peel and cube, boil until tender, then drain thoroughly and let the steam escape before mashing.

Pro tip: Mash until smooth and measure after mashing. Sweet potatoes vary a lot in size.

Sweet potato cake (step-by-step)

This makes a generous 9x13 cake or two 9-inch rounds.

What you will need

• 2 cups mashed cooked sweet potato (about 2 medium to large)
• 2 1/2 cups all-purpose flour
• 2 teaspoons baking powder
• 1 teaspoon baking soda
• 2 teaspoons ground cinnamon
• 1/2 teaspoon ground ginger (optional)
• 1/4 teaspoon nutmeg (optional)
• 1 teaspoon fine salt
• 1 cup brown sugar, packed
• 1/2 cup granulated sugar
• 1 cup neutral oil
• 4 large eggs, room temperature
• 1 tablespoon vanilla extract
• 1 cup buttermilk (or 1 cup milk + 1 tablespoon lemon juice, rested 5 minutes)

Instructions

1. Prep your pan and oven. Heat oven to 350°F. Grease a 9x13 pan (or two 9-inch round pans) and line the bottom with parchment if you want easy removal.
2. Mix the dry ingredients. In a medium bowl whisk flour, baking powder, baking soda, cinnamon, ginger, nutmeg, and salt.
3. Mix the wet ingredients. In a large bowl whisk brown sugar, granulated sugar, oil, eggs, and vanilla until glossy and well combined.
4. Add the sweet potato. Whisk in the mashed sweet potato until smooth. A few tiny lumps are fine, but you want it mostly even.
5. Combine. Add the dry ingredients in two additions, alternating with the buttermilk. Switch to a spatula and fold gently just until no dry streaks remain. Overmixing makes cake tough, so stop as soon as it looks uniform.
6. Bake. Pour into the pan(s) and smooth the top. Bake until a toothpick comes out with a few moist crumbs, or the center reads about 200 to 205°F.
7. Cool completely. Cool in the pan for 15 to 20 minutes, then turn out (for layers) or cool fully in the pan (for sheet cake). Frosting and warm cake do not get along.

Bake times and pans

• 9x13 sheet cake: 35 to 45 minutes
• Two 9-inch rounds: 28 to 35 minutes
• Cupcakes: 18 to 22 minutes
• Bundt pan: 45 to 60 minutes

Ovens vary, and sweet potato moisture varies too. Start checking on the early side and look for a set center that springs back lightly.

Bundt note: This recipe makes a lot of batter. Use a 10 to 12 cup Bundt pan and fill it no more than about 2/3 to 3/4 full. If you have extra batter, bake the rest as a few cupcakes so you are not risking an overflow situation.

Cream cheese frosting

This frosting is tangy, not overly sweet, and sturdy enough to layer.

How much frosting do you need?

• 9x13 sheet cake: 1 batch gives a nice, classic layer. For extra thick swoops, make 1 1/2 batches.
• Two 9-inch layers: 1 batch is usually enough for filling plus a thinner coat on the outside. For a generous finish (or any piping), make 1 1/2 batches.
• Cupcakes: 1 batch generously frosts about 18 to 24 cupcakes, depending on how enthusiastic you are.

Ingredients

• 8 ounces cream cheese, softened
• 1/2 cup unsalted butter, softened
• 3 to 4 cups powdered sugar, to taste
• 2 teaspoons vanilla extract
• Pinch of salt

Instructions

1. Beat cream cheese and butter until completely smooth and fluffy, 2 to 3 minutes.
2. Beat in vanilla and salt.
3. Add powdered sugar 1 cup at a time, mixing until thick and creamy. Use 3 cups for a softer frosting, 4 cups for piping or a more structured layer cake.

My best frosting tip:

Flavor add-ins

Sweet potato cake is fabulous plain, but you can absolutely make it your own.

• Chopped toasted pecans or walnuts: Fold 1 cup into the batter, or sprinkle on top of the frosting.
• Orange zest: Add 1 to 2 teaspoons to the batter for a bright lift.
• Bourbon or maple: Add 1 tablespoon bourbon or swap 2 tablespoons of sugar for maple syrup (reduce buttermilk slightly if batter feels loose).
• Chocolate chips: Mini chips work best, about 3/4 cup.
• Spice tweaks: A pinch of cloves is bold but lovely if you like deep spice.

Little baker trick: If you are adding nuts or chips, toss them with 1 teaspoon of flour before folding in. It helps keep them from sinking to the bottom.

Troubleshooting

My cake is dense

• Sweet potatoes were too wet. Next time roast or let boiled potatoes steam dry before mashing.
• Overmixed batter. Fold just until combined.
• Expired leaveners. Baking powder and soda lose strength over time.

My cake sank in the middle

• Underbaked. Check the center with a toothpick and look for a gentle spring back, or aim for about 200 to 205°F in the center.
• Oven door opened too early. Try not to peek in the first 25 minutes.

My frosting is runny

• Cream cheese was too soft or warm. Chill the bowl 20 minutes and re-beat.
• You used spreadable tub cream cheese. For thick frosting, use brick-style cream cheese.

Make-ahead, storing, freezing

Make ahead

• Sweet potatoes: Cook and mash up to 3 days ahead. Store airtight in the fridge.
• Cake layers: Bake a day ahead, wrap tightly, and keep at room temperature.
• Frosting: Make up to 3 days ahead and refrigerate. Let soften and re-whip before using.

Storing

• Frosted cake: Store covered in the fridge for up to 5 days. Let slices sit at room temperature 20 to 30 minutes before serving for the best texture.
• Unfrosted cake: Room temperature for 2 days, wrapped well.

Freezing

• Unfrosted: Wrap layers in plastic wrap and then foil. Freeze up to 3 months.
• Frosted: Freeze slices on a sheet pan until firm, then wrap and store. Thaw overnight in the fridge.

Serving ideas

This cake is a star on its own, but if you want to make it feel extra special:

• A sprinkle of toasted pecans and a pinch of cinnamon on top
• A drizzle of warm caramel sauce right before serving
• Freshly brewed coffee or chai on the side
• For a dinner party, serve small squares with a dollop of lightly sweetened whipped cream

Sweet potato cake FAQ

Can I use canned sweet potato?

Yes, as long as it is plain canned sweet potato or plain sweet potato puree. Avoid sweet potato pie filling because it includes added sugar and spices that throw off the balance.

Is sweet potato cake the same as sweet potato pie?

Not quite. Sweet potato pie is a custard filling in a crust. Sweet potato cake is a true cake with flour and leaveners, with sweet potato acting like a moisture-rich flavor boost.

Can I make it without buttermilk?

Absolutely. Use the quick sour milk substitute: 1 cup milk mixed with 1 tablespoon lemon juice or white vinegar. Let it sit 5 minutes, then use as buttermilk.

Can I make this into a layer cake?

Yes. Two 9-inch layers work beautifully. If you want three layers, bake in three 8-inch pans and start checking around 22 to 26 minutes.

What spices taste best with sweet potato?

Cinnamon is the classic. Ginger, nutmeg, and a tiny pinch of cloves deepen the flavor without overpowering that sweet potato warmth.

A cozy pep talk

If you are new to baking cakes from scratch, sweet potato cake is such a friendly place to start. The sweet potato gives you a lot of forgiveness because it naturally keeps things moist. Measure carefully, do not overmix, and let it cool completely before frosting. You have got this.