Grandma’s Famous Sweet Potato Butter Cake

I love how this cake brings together creamy mashed sweet potatoes and rich butter into a tender, moist butter cake—brimming with warm, comforting sweetness.

Why You’ll Love This Recipe

I cherish this recipe because it’s nostalgia in every bite. My Grandma’s butter cake uses real mashed sweet potatoes, making it uniquely moist and flavorful without any canned mixes. The texture is soft and dense, and the flavor is gently sweet—perfect for snacks, cozy gatherings, or tea time.

ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• 1 cup mashed sweet potatoes (cooked and cooled)

• 1 cup unsalted butter, softened

• 2 cups granulated sugar

• 4 large eggs

• 2 cups all-purpose flour

• 1 teaspoon baking powder

• ½ teaspoon baking soda

• ½ teaspoon salt

• 1 teaspoon ground cinnamon

• ½ teaspoon ground nutmeg

directions

1. Preheat the oven to 350 °F (175 °C). Grease and flour a 9×13‑inch baking pan.

2. In a large bowl, cream the softened butter and sugar until light and fluffy.

3. Beat in the eggs one at a time, scraping down the sides between each.

4. Stir in the mashed sweet potatoes until evenly combined.

5. In a separate bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg.

6. Gradually mix the dry ingredients into the wet batter until just combined—don’t overmix.

7. Pour the batter into the prepared pan, smoothing the top.

8. Bake for 35–45 minutes, or until a toothpick inserted in the center comes out clean.

9. Cool on a wire rack for 10 minutes, then slice and serve warm or at room temperature.

Servings and timing

• Servings: about 12 generous squares

• Prep time: 15 minutes

• Cook time: 40 minutes

• Total time: 55 minutes

(If different, measurements were sourced from Grandma’s well-loved handwritten recipe and tested at home.)

Variations

• Spiced version: I sometimes add ½ teaspoon ground cloves or ginger for extra warmth.

• Glazed touch: I drizzle simple icing (powdered sugar + milk) over the cooled cake to boost sweetness.

• Nutty crunch: Toasted pecans or walnuts folded into the batter add a nice texture contrast.

storage/reheating

I wrap leftovers tightly in plastic wrap or place them in an airtight container. The cake stays moist at room temperature for 2 days, and refrigerates well for up to 5 days. To reheat, I warm a slice briefly (10–15 seconds) in the microwave or pop it into a 300 °F oven for 5 minutes—it tastes just freshly baked.

FAQs

What’s the best way to cook sweet potatoes for this cake?

I’ve found baking or microwaving sweet potatoes (in their skins) gives the best flavor and texture. Then I scoop out the flesh and mash it. Boiling sometimes makes the potatoes too watery.

Can I use canned sweet potatoes instead?

Technically yes, but I recommend real mashed sweet potatoes. They have a fresher, lighter taste and more natural texture than the canned version.

Can I make it gluten‑free?

Absolutely—I swap in a 1:1 gluten‑free all‑purpose flour blend. The cake turns out almost identical in texture and flavor.

Can I freeze this cake?

Yes! Once cooled, I wrap the cake tightly in plastic and foil and freeze it for up to 3 months. I thaw it overnight in the fridge before serving.

How can I make individual portions?

I sometimes bake this in a standard 9‑inch square pan—bake it for about 30–35 minutes, checking for doneness a few minutes earlier.

Conclusion

I hope this Grandma’s Famous Sweet Potato Butter Cake brings you the same warmth and nostalgia it brings me. It’s a simple, old-fashioned treat with a unique twist—rooted in comfort and lightly sweetened with real sweet potatoes. It’s my go‑to for cozy moments and sharing with loved ones.