This southern 3-ingredient blackberry dump cake is the kind of simple, old-fashioned dessert that shows up on Sunday tables all over the rural Midwest and South. My aunt has made a version of this for as long as I can remember, always in her well-seasoned cast iron skillet, and the whole family hovers in the kitchen waiting to claim those crunchy, buttery corner pieces. It’s the kind of recipe you pull out when berries are plentiful, company is coming, and you don’t want to fuss with pastry dough or long ingredient lists—just open, dump, and bake until the berries bubble up and the top turns golden and crisp.
Serve this blackberry dump cake warm right out of the cast iron skillet, with big spoonfuls scooped so you get both the soft, jammy berries and the crunchy, buttery crust. A scoop of vanilla ice cream or a dollop of lightly sweetened whipped cream melts into the warm berries and makes it feel like a Sunday supper dessert. It’s also lovely with a cup of coffee in the afternoon or alongside a simple, hearty meal like pot roast or fried chicken, when you want something cozy and familiar to finish things off.
Southern 3-Ingredient Blackberry Dump CakeServings: 8
Ingredients
4 cups fresh or frozen blackberries (about 1 1/4 pounds)
1 box (15.25 ounces) yellow cake mix, dry
1 cup (2 sticks, 8 ounces) unsalted butter, melted
Directions
Preheat your oven to 350°F (175°C). Place a 10–12 inch cast iron skillet on the counter so it’s ready to fill. If your skillet is very well seasoned, you don’t need to grease it; otherwise, lightly butter the bottom and sides.
Add the blackberries directly to the cast iron skillet, spreading them into an even layer. If you’re using frozen berries, there’s no need to thaw them first—just break up any big clumps so they’re scattered evenly.
Sprinkle the dry yellow cake mix evenly over the berries. Use your hand or a spoon to gently spread the mix so it covers the fruit from edge to edge, all the way into the corners. Do not stir; you want distinct layers so the top bakes up crisp and the berries bubble underneath.
Slowly drizzle the melted butter over the entire surface of the dry cake mix, making sure to cover as much of the top as you can, especially around the edges and corners where the best crunchy bits form. A few small dry spots are fine; they’ll pick up moisture from the berries as it bakes.
Place the skillet on the middle rack of the preheated oven. Bake for 40–50 minutes, or until the blackberry filling is bubbling up around the edges and through a few spots in the middle, and the top is deep golden brown and crisp. The corners should look especially caramelized and crunchy.
Carefully remove the skillet from the oven and set it on a heatproof surface. Let the dump cake rest for at least 15–20 minutes; the bubbling juices will thicken slightly as it cools, and the crunchy top will firm up, especially around the edges.
Serve warm, scooping down through the crust to get both berries and topping in each serving. Those dark, caramelized corners are the prized pieces, so be ready for a little friendly family tussle over them.
Variations & Tips
For a slightly sweeter or more jammy filling, you can toss the berries with 2–3 tablespoons of sugar before adding the cake mix, but that will technically add a fourth ingredient; my aunt usually relies on the natural sweetness of ripe blackberries and the cake mix itself. If blackberries are scarce, you can substitute an equal amount of raspberries, blueberries, or a mix of berries and still keep the recipe to three ingredients. To add a bit of tang, some folks like to tuck a few spoonfuls of lemon curd between the berries, but again, that moves it beyond the strict three-ingredient version. For a deeper, more caramelized flavor, use a butter or golden cake mix instead of plain yellow. If you prefer a softer top with fewer crunchy bits, cover the skillet loosely with foil for the first 20 minutes of baking, then remove it so the crust can brown. Food safety notes: If using frozen berries, keep them in the freezer until you’re ready to assemble so they don’t sit at room temperature too long; there’s no need to thaw before baking. Always melt butter gently over low heat or in short bursts in the microwave to avoid splattering and burns. Use oven mitts when handling the cast iron skillet, as the handle stays extremely hot during and after baking. Leftover dump cake should be cooled to room temperature, then covered and refrigerated within 2 hours; it will keep safely for 3–4 days. Reheat individual portions in the microwave or warm the skillet in a low oven until heated through.
