Grandma’s Famous Sweet Potato Butter Cake feels like a warm hug from the oven. This soft, buttery cake mixes sweet potato and spices into a cozy dessert that fills your kitchen with cinnamon and baked butter smells. If you like hearty sweet potato dishes, you might also enjoy our Best Sweet Potato Casserole. Make this cake when you want an easy, homey treat for family nights or holiday guests.
Why Make This Recipe
- Quick & Easy: Simple steps and common pantry ingredients.
- Family Favorite: Mild spice and buttery texture please kids and adults.
- Budget-Friendly: Uses pantry staples and seasonal sweet potatoes.
This recipe stands out because the mashed sweet potato keeps the cake moist and rich without being heavy. The buttery top caramelizes just enough for a soft crust that cracks with a sweet smell. It brings comfort and little bites of nostalgia — like a childhood kitchen filled with spice and warmth. Serve it when you want to bring everyone together, or pair it after a savory meal like a chicken sweet potato curry for a cozy dinner.
Ingredients
For the cake:
- 2 cups mashed cooked sweet potato (about 2 medium sweet potatoes), cooled
- 1 cup (2 sticks) unsalted butter, softened
- 1 1/2 cups granulated sugar
- 3 large eggs, room temperature
- 1 teaspoon vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
- 1 teaspoon ground cinnamon
- 1/2 teaspoon ground nutmeg
- 1/2 cup milk (whole or 2%)
For the topping (optional):
- 2 tablespoons unsalted butter, melted
- 2 tablespoons brown sugar, packed
- Pinch of cinnamon
Notes:
- Use unsalted butter so you can control the salt.
- Mash sweet potato until smooth for an even texture.
- Room temperature eggs mix better and give a lighter cake.
How to Make Grandma’s Famous Sweet Potato Butter Cake
- Preheat the oven to 350°F (175°C). Grease and flour a 9×13-inch pan or line it with parchment. (Why this matters: a hot oven helps the cake rise evenly and the pan prep prevents sticking.)
- Cook and mash sweet potatoes. Pierce whole sweet potatoes and bake or microwave until very soft, then cool and mash until smooth. (Mini-tip: steaming keeps them less watery than boiling.)
- In a large bowl, cream the softened butter and sugar until light and slightly fluffy. Add eggs one at a time, beating well after each. Stir in vanilla. (Why: this adds air for a tender crumb.)
- In a separate bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
- Add the dry mix to the butter mixture in three parts, alternating with milk and ending with dry mix. Fold in the mashed sweet potato until just combined. Do not overmix. (Mini-tip: overmixing makes the cake dense.)
- Pour batter into the prepared pan and smooth the top with a spatula.
- Mix the topping: stir melted butter, brown sugar, and a pinch of cinnamon. Sprinkle over the batter for a buttery crust. (Optional: skip this for a plain top.)
- Bake 40–50 minutes, or until a toothpick in the center comes out with a few moist crumbs. The top will smell warm and spiced; edges should pull slightly from the pan.
- Let the cake cool in the pan on a wire rack for 15–20 minutes before slicing so it sets and stays moist.
How to Serve Grandma’s Famous Sweet Potato Butter Cake
- Serve warm with a scoop of vanilla ice cream or a dollop of whipped cream for contrast in temperature and texture.
- Dust the top with a little powdered sugar and add toasted pecans for crunch.
- Pair slices with afternoon tea or after a savory fall meal for a cozy finish.
How to Store Grandma’s Famous Sweet Potato Butter Cake
- Short term: Keep the cake in an airtight container at room temperature for up to 2 days.
- Refrigerate: Store covered in the fridge for 3–4 days. Bring to room temperature or warm slightly before serving.
- Freeze: Wrap individual slices tightly in plastic, then foil, and freeze for up to 2 months. Thaw overnight in the fridge and warm in a 325°F oven for 10–15 minutes.
- Reheat: Warm slices in the microwave for 15–25 seconds or in the oven at 325°F until just warm to keep moisture.
Tips to Make Grandma’s Famous Sweet Potato Butter Cake
- Use cooled mashed sweet potato to avoid adding extra moisture to the batter.
- Measure flour correctly (spoon into cup and level) to prevent a dry, heavy cake.
- Check doneness with a toothpick at 40 minutes to avoid overbaking.
- For deeper flavor, roast sweet potatoes with their skins on instead of boiling.
- Let the cake rest before slicing to keep neat pieces.
Variation (if any)
- Gluten-free: Substitute a 1:1 gluten-free flour blend and add 1/4 teaspoon xanthan gum if your blend lacks it.
- Vegan: Use 3 flax eggs (1 tablespoon ground flax + 3 tablespoons water each), replace butter with coconut oil, and use plant milk.
FAQs
Can I use canned sweet potato or pumpkin instead of fresh?
Yes. Use canned sweet potato or pumpkin purée (not pie filling). Drain any excess liquid and measure 2 cups. Fresh gives the best flavor and texture, but canned works in a pinch.
Can I make this cake ahead of time?
Yes. Bake the cake, cool completely, then cover and refrigerate for up to 3 days. Reheat gently before serving. You can also freeze baked slices for longer storage.
What if the cake is too wet in the middle?
If the center stays wet after the recommended time, tent loosely with foil and bake 5–10 minutes longer, checking every few minutes. Make sure your sweet potato purée isn’t too watery.
Can I swap spices or use less sugar?
Yes. Reduce sugar by up to 1/4 cup for a less sweet cake. Try adding a little ginger or allspice for a different warm spice profile.
Conclusion
Thanks for baking Grandma’s Famous Sweet Potato Butter Cake with us — it’s a simple, comforting treat that fills the house with warm spice and buttery aroma. If you want a quick reference or holiday ideas, check out this Grandma’s Famous Sweet Potato Butter Cake Holiday Favorite. Leave a comment and a star rating to tell us how it turned out. Pin or share this on Pinterest or Facebook to spread the cozy vibes. What twist did you try? Let us know below!
Sweet Potato Butter Cake
Ingredients
For the cake
- 2 cups mashed cooked sweet potato (about 2 medium sweet potatoes), cooled Use cooled mashed sweet potato to avoid adding extra moisture to the batter.
- 1 cup unsalted butter, softened Use unsalted butter to control the salt.
- 1.5 cups granulated sugar Reduce by up to 1/4 cup for a less sweet cake.
- 3 large eggs, room temperature Room temperature eggs mix better and give a lighter cake.
- 1 teaspoon vanilla extract
- 2 cups all-purpose flour Measure flour correctly to prevent a dry, heavy cake.
- 1 teaspoon baking powder
- 0.5 teaspoon baking soda
- 0.5 teaspoon salt
- 1 teaspoon ground cinnamon Try adding a little ginger or allspice for a different flavor.
- 0.5 teaspoon ground nutmeg
- 0.5 cup milk (whole or 2%)
For the topping (optional)
- 2 tablespoons unsalted butter, melted
- 2 tablespoons brown sugar, packed
- 1 pinch cinnamon
Instructions
Preparation
- Preheat the oven to 350°F (175°C). Grease and flour a 9x13-inch pan or line it with parchment.
- Cook and mash sweet potatoes. Pierce whole sweet potatoes and bake or microwave until very soft, then cool and mash until smooth.
- In a large bowl, cream the softened butter and sugar until light and slightly fluffy. Add eggs one at a time, beating well after each. Stir in vanilla.
- In a separate bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
- Add the dry mix to the butter mixture in three parts, alternating with milk and ending with dry mix. Fold in the mashed sweet potato until just combined.
- Pour batter into the prepared pan and smooth the top with a spatula.
Topping and Baking
- Mix the topping: stir melted butter, brown sugar, and a pinch of cinnamon. Sprinkle over the batter for a buttery crust.
- Bake for 40–50 minutes, or until a toothpick in the center comes out with a few moist crumbs. Let the cake cool in the pan on a wire rack for 15–20 minutes before slicing.