This sweet potato dump cake has a creamy, lightly spiced sweet potato layer beneath a crisp, buttery yellow cake mix topping. It is a scoopable 9×13-inch dessert, so you get the comfort of sweet potato pie without making a crust.
The shortcut is simple: measure cooked mashed sweet potatoes, whisk the filling, sprinkle dry cake mix over it, and cover the top with melted butter. Let the baked dessert rest before serving so the filling can firm up.
Recipe at a glance: 12 servings | Prep: 15 minutes | Bake: 50 to 60 minutes | Rest: 30 minutes | Total: about 1 hour 35 minutes to 1 hour 45 minutes.
Why This Easy Sweet Potato Dump Cake Works
Yellow cake mix forms a tender, golden topping without a separate batter. Evaporated milk and eggs give the sweet potato layer a soft custard texture, while brown sugar and a small amount of cinnamon, ginger, and nutmeg add warmth. You can start with drained canned sweet potatoes or cooked fresh ones, as long as you measure 2 cups after cooking or draining.
Ingredients for Sweet Potato Dump Cake
For the sweet potato filling
Use 2 cups cooked mashed sweet potatoes, 1 can (12 fluid ounces) evaporated milk, 3 large eggs, 1/2 cup packed light brown sugar, 1 teaspoon cinnamon, 1/2 teaspoon ground ginger, 1/4 teaspoon nutmeg, 1 teaspoon vanilla extract, and 1/4 teaspoon fine salt. Drain canned sweet potatoes well before mashing and measuring. Choose plain sweet potatoes when possible; syrup-packed ones can change the sweetness.
For the topping
Use one 15.25-ounce box of yellow cake mix and 1 cup (2 sticks) melted unsalted butter. Sprinkle the mix on dry. Do not add the eggs, water, or oil called for on its box.
How to Make Sweet Potato Dump Cake with Yellow Cake Mix
1. Prepare the pan and filling
Heat the oven to 350°F and lightly grease a 9×13-inch baking dish at least 2 inches deep. Whisk the eggs first, then add the mashed sweet potatoes, evaporated milk, sugar, spices, vanilla, and salt. Whisk until mostly smooth and spread the filling evenly in the pan.
2. Add the dry mix and butter
Sprinkle the dry cake mix all the way to the corners. Break up large clumps as you go. Drizzle melted butter in thin passes over the entire surface and gently spread it over any wide dry spots. Keep the topping and filling in separate layers.
3. Bake and rest
Bake for 50 to 60 minutes, checking at 45 minutes. Look for a golden top, set edges, and a center that jiggles slightly rather than sloshes. An instant-read thermometer inserted into the custard layer near the center should read at least 160°F. If the topping colors too fast, loosely cover it with foil and bake in short increments. Rest the dish on a rack for at least 30 minutes before scooping.
Canned or Fresh Sweet Potatoes?
For the quickest version, drain canned sweet potatoes thoroughly, mash, and measure 2 cups. If they were packed in syrup, the finished cake may taste sweeter. For fresh sweet potatoes, cook until tender, cool enough to handle, mash smooth, and measure the same 2 cups. Avoid adding cooking water or syrup to the filling; extra liquid makes it slower to set.
Tips and Troubleshooting
Why is there dry cake mix on top?
A wide dry patch usually means the butter missed part of the surface. Before baking, spread melted butter gently across any visible powder. Do not stir the layers together.
Why is the filling loose?
The sweet potatoes may have carried extra liquid, or the center may need more time. Drain and measure them before mixing. Bake until the middle has only a gentle jiggle, then let the cake rest for 30 minutes. A warm scoop will be softer than a chilled portion.
Can I change the cake mix or spices?
A same-size spice cake mix will make the topping more strongly spiced; keep the filling spices modest if you try it. Different box weights can leave an uneven topping, so use 15.25 ounces. Add or reduce the listed spices to taste, but changing the eggs or milk can affect how the filling sets.
Make-Ahead, Storage, and Reheating
You can bake the cake the day before and refrigerate it covered after it cools. Because this filling contains eggs and milk, put leftovers in the refrigerator within 2 hours and use them within 3 to 4 days. Freeze individual portions for up to 2 months for best quality. Thaw in the refrigerator; the topping will soften after storage. Warm a portion gently, or serve it chilled. See the FoodSafety.gov cold-storage chart for egg-containing baked dishes and pies.
Frequently Asked Questions
Is this a fluffy cake or a spoon dessert?
It is a spoon dessert. The bottom is a soft sweet potato custard, and the top is buttery cake mix. Resting helps it scoop more cleanly, but it will not have the crumb of a layer cake.
Can I eat the cake mix before baking?
No. Dry cake mix contains raw flour. The FDA’s raw-flour safety guidance says not to taste raw batter or dough.
What else can I serve for a fall dessert?
For another cake-mix dessert with a different filling, try our pumpkin dump cake. If you want a nutty holiday variation, the pecan pie dump cake offers a different texture and flavor.
Sweet Potato Dump Cake Recipe Card
Sweet Potato Dump Cake with Yellow Cake Mix
Ingredients
Method
- Heat the oven to 350°F with a rack in the center. Lightly grease a 9×13-inch baking dish at least 2 inches deep. Melt the butter and let it cool slightly while you make the filling.
- Whisk the eggs in a large bowl until blended. Add the mashed sweet potatoes, evaporated milk, brown sugar, cinnamon, ginger, nutmeg, vanilla, and salt. Whisk until mostly smooth, scraping the bottom of the bowl. Small sweet potato flecks are fine. Pour the filling into the prepared dish and spread evenly.
- Sprinkle the dry yellow cake mix evenly over the filling, reaching the corners and breaking up large lumps. Do not stir the cake mix into the filling.
- Slowly drizzle the melted butter across the cake mix in thin passes. Gently spread it over any large dry patches with the back of a spoon without mixing the layers.
- Bake for 50 to 60 minutes, checking at 45 minutes. The top should be golden and the edges set; the center should jiggle slightly rather than slosh when the pan is gently nudged. An instant-read thermometer inserted into the custard layer near the center should read at least 160°F. If the topping browns too quickly, loosely tent with foil and continue baking in 5-minute increments.
- Set the baking dish on a rack for at least 30 minutes before scooping. The filling firms as it cools. Serve warm, or chill for neater portions.