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Blueberry Dump Cake With Buttery Topping
This blueberry dump cake turns a bag of fresh or frozen blueberries into a warm, jammy, cobbler-style dessert with a golden, buttery topping. Toss the berries with a little sugar, lemon and cornstarch right in the baking dish, sprinkle dry cake mix over the top, cover it with butter, and bake. No mixing bowl and no mixer, and about 10 minutes of hands-on time. Serve it warm with vanilla ice cream.
Below you’ll find the ingredients, fresh vs frozen vs pie-filling options, step-by-step instructions, tips for a crisp topping with no dry spots, variations, storage and FAQs. The printable recipe card is at the bottom.
Why You’ll Love This Recipe
- Real fruit, less sugar. Fresh or frozen blueberries with a little sugar and lemon taste brighter and less sweet than canned pie filling.
- Works all year. Use fresh berries in summer and frozen berries the rest of the year, straight from the freezer.
- Almost no work. Everything is layered in one dish.
- Crowd-sized. A 9×13 pan serves 12.
Ingredients You Need
- Blueberries, 5 cups (about 1â…” lb / 750 g), fresh or frozen (don’t thaw frozen berries).
- Granulated sugar, ½ cup (100 g). Use ⅓ cup if your berries are very sweet.
- Cornstarch, 2 tablespoons. It thickens the juices so the filling is jammy, not runny.
- Lemon, 1: 1 teaspoon zest and 1 tablespoon juice.
- White, yellow or lemon cake mix, 1 box (13.25 to 15.25 oz), dry. Don’t add the eggs, oil or water from the box.
- Butter, ¾ cup (1½ sticks / 170 g), cold and thinly sliced, or melted.
- Optional topping: 1 tablespoon sugar mixed with ½ teaspoon cinnamon, or ½ cup sliced almonds.
Fresh, Frozen or Pie Filling?
| Blueberries | How to use them | Bake time at 350°F |
|---|---|---|
| Fresh | Rinse, drain well and toss with the sugar, cornstarch and lemon | 45 to 55 minutes |
| Frozen | Use straight from the freezer; toss with the sugar, cornstarch and lemon | 55 to 65 minutes |
| Blueberry pie filling | Use 2 cans (21 oz each) and skip the sugar, cornstarch and lemon juice | 45 to 50 minutes |
Pie filling is the fastest shortcut, but the filling is sweeter and softer. Fresh or frozen berries give a fruitier, tangier result.
Equipment You Need
- A 9×13-inch baking dish.
- A rimmed baking sheet to set it on, to catch bubbling juice.
- A spoon or spatula and a sharp knife for slicing the butter.
How to Make Blueberry Dump Cake (Step by Step)
1. Heat the oven
Heat the oven to 350°F (175°C) with a rack in the center. Lightly grease the baking dish.
2. Toss the berries in the dish
Add the blueberries, sugar, cornstarch, lemon zest and lemon juice to the dish and stir until the berries are evenly coated. Spread them in an even layer.
3. Add the cake mix
Sprinkle the dry cake mix evenly over the berries, breaking up any lumps. Gently level it with the back of a spoon, but don’t stir it in or press it down.
4. Cover with butter
Lay thin slices of cold butter over the entire surface, edge to edge, so very little dry mix shows. Or drizzle melted butter slowly and evenly over the top. Sprinkle with cinnamon sugar or almonds, if using.
5. Bake
Set the dish on the baking sheet and bake for 45 to 55 minutes (55 to 65 minutes for frozen berries), until the top is deep golden and the blueberry juices are bubbling thickly around the edges. If you see dry patches after 30 minutes, dab them with a little melted butter.
6. Cool and serve
Cool for at least 20 minutes so the juices can thicken. Serve warm with vanilla ice cream or whipped cream.
Tips for a Crisp, Golden Topping
- Don’t skip the cornstarch. Blueberries release a lot of juice; cornstarch turns it into a glossy, jammy sauce.
- Bake until the juices bubble thickly. Cornstarch only thickens once it boils, so the filling needs to bubble, not just simmer at the edges.
- Cover the cake mix completely with butter. Uncovered mix stays powdery.
- Don’t stir. Mixing the cake mix into the fruit makes it gummy.
- Let it cool. The filling is runny when it’s very hot and sets up as it cools.
- Don’t taste the raw cake mix. It contains raw flour, which isn’t safe until baked. See the FDA’s advice on handling flour safely.
How to Choose and Prep Blueberries
- Fresh: look for firm, plump, deep blue berries with a silvery bloom and no juice stains in the container. Skip soft, wrinkled or moldy ones.
- Rinse just before using, not before storing; moisture makes berries spoil faster. Drain them well, or the extra water thins the filling.
- Pick out stems and any soft berries.
- Wild frozen blueberries are small and intense; they work beautifully here and release a little more juice, so keep the full 2 tablespoons of cornstarch.
- Store fresh berries unwashed in the fridge and use them within about a week.
Common Mistakes to Avoid
- Thawing frozen berries first. They collapse and flood the dish. Bake them frozen.
- Pulling it out too early. A golden top doesn’t mean the filling is ready. Wait for thick bubbles at the edges.
- Leaving bare patches of cake mix. They bake into powdery spots. Butter the corners too.
- Using a small, deep dish. The topping stays raw underneath. A 9×13 pan gives the right depth.
- Serving straight from the oven. The filling needs 20 minutes to set.
Easy Variations
- Lemon blueberry: use lemon cake mix and add the zest of a second lemon to the berries.
- Blueberry peach: use 3 cups blueberries and 3 cups sliced peaches (fresh or frozen).
- Mixed berry: use any mix of blueberries, raspberries and blackberries.
- Cream cheese swirl: drop small spoonfuls of 4 oz softened cream cheese beaten with 2 tablespoons sugar over the berries before adding the cake mix.
- Crunchy top: add ½ cup chopped pecans or sliced almonds over the butter.
- Other fruit: try our 4-ingredient cherry dump cake, apple dump cake or pumpkin dump cake. For chocolate lovers, there’s our chocolate dump cake.
Adjusting the Sweetness
Blueberries vary a lot. Peak-season berries can be very sweet, while early or frozen cultivated berries can be tart. Taste a few before you start:
- Very sweet berries: use â…“ cup sugar and the full tablespoon of lemon juice.
- Tart berries: use the full ½ cup sugar.
- Less sweet overall: use a white or yellow cake mix rather than butter golden, skip the cinnamon sugar, and serve with plain whipped cream or Greek yogurt instead of ice cream.
Remember that the cake mix topping is already sweet, so the fruit layer can be a little tart and the dessert will still taste balanced.
Make It Ahead
- Same day: bake up to 4 hours ahead, leave it at room temperature loosely covered, and rewarm it for 10 minutes at 325°F (165°C) before serving.
- Prep ahead: toss the berries with the sugar, cornstarch and lemon in the dish and refrigerate for up to 1 day. Add the cake mix and butter right before baking, so the mix doesn’t soak up the juice and turn pasty.
- For a crowd: bake two pans on separate racks, swapping them halfway, and add 5 to 10 minutes.
What to Serve With It
- Vanilla ice cream or frozen yogurt
- Lightly sweetened whipped cream
- Plain Greek yogurt with a drizzle of honey, for a breakfast treat
- After a summer cookout, like our grilled New York strip steak
Browse all our cake recipes for more easy desserts.
How to Store, Freeze and Reheat
- Room temperature: cover and keep for up to 1 day.
- Refrigerate: cover and keep for up to 4 days. The topping softens in the fridge.
- Freeze: cool completely, wrap well, and freeze for up to 3 months. Thaw overnight in the fridge.
- Reheat: microwave single servings for 20 to 30 seconds, or warm the dish, covered with foil, in a 325°F (165°C) oven for 15 to 20 minutes, uncovering for the last 5 minutes to crisp the top.
Blueberry Dump Cake FAQs
Do I need to thaw frozen blueberries for dump cake?
No. Use them straight from the freezer and add about 10 minutes to the baking time. Thawed berries release their juice early and can make the topping soggy.
Why is my blueberry dump cake runny?
It wasn’t baked long enough for the juices to boil and thicken, it was served too hot, or the cornstarch was left out. Bake until the juices bubble thickly and let it cool for 20 minutes.
What cake mix is best for blueberry dump cake?
White, yellow, butter golden and lemon cake mixes all work well. Lemon gives the brightest flavor.
Can I use blueberry pie filling?
Yes. Use 2 cans (21 oz each) and skip the sugar, cornstarch and lemon juice. Bake for 45 to 50 minutes.
Can I make it in a smaller pan?
Yes. Halve everything and bake in an 8×8-inch dish for 35 to 45 minutes (longer for frozen berries).
Blueberry Dump Cake Recipe Card
Calories are an estimate per serving (1/12 of the pan, without toppings) based on USDA FoodData Central values for raw blueberries, sugar, cornstarch, yellow cake mix (15.25 oz box) and butter.
Blueberry Dump Cake
Ingredients
Equipment
Method
- Heat the oven to 350°F (175°C) and grease a 9×13-inch baking dish.
- Toss the blueberries, sugar, cornstarch, lemon zest and lemon juice in the dish and spread evenly.
- Sprinkle the dry cake mix evenly over the berries, breaking up lumps. Level gently; do not stir.
- Cover the whole surface with thin slices of cold butter, or drizzle evenly with melted butter. Add the cinnamon sugar if using.
- Set on a baking sheet and bake 45 to 55 minutes (55 to 65 for frozen berries), until golden and the juices bubble thickly. Dab dry spots with melted butter after 30 minutes.
- Cool at least 20 minutes and serve warm with ice cream or whipped cream.
