Preheat the oven to 350F degrees. Spray a 9x13-inch baking dish with nonstick cooking spray (I like the kind that has flour in it, like Baker’s Joy.)
Pour 2 cups frozen blueberries (thawed) into the baking dish then evenly sprinkle 2 Tablespoons packed brown sugar on top.
Then add the 21 ounce can blueberry pie filling and 1 teaspoon vanilla extract.
Gently mix to combine all the ingredients in the baking dish. .
Next, sprinkle the 1 box white cake mix evenly over the blueberry mixture.
Place the ½ cup (1 stick) salted butter, cut into 20 slices evenly over the cake mix. Don’t mix.
Bake for about 43 to 45 minutes or until the top is nice and golden.
Let cool for a few minutes. Then serve warm with whipped cream or a scoop of vanilla ice cream on top!
Notes
Please refer to my FAQ’s and ingredient list above for other substitutions or for the answers to the most common questions.
You can substitute the white cake mix for a yellow cake mix or vanilla cake mix.
If your blueberries are already very sweet, you don't need to add the brown sugar. However, I don't add much here and I think it adds a nice flavor in the background that doesn't add a ton of sweetness.
I used salted butter but unsalted butter would work as well.
You can use fresh blueberries instead of frozen.
You can skip the blueberries altogether and just use 2 cans of blueberry pie filling (just don’t add the brown sugar since the pie filling has plenty of sugar in it.)
You can trade out the blueberry pie filling and fruit choice if desired.
Freezing dump cake is possible, let it cool at room temperature and then store in a freezer safe container for up to 3 months.
The vanilla extract is optional but I think it really adds a depth of flavor to the pie filling and makes it taste a bit more homemade. I think almond extract would be yummy too.