This is my simplified, straight-from-Grandma version of lemon dump cake: just lemon pie filling, boxed yellow cake mix, and butter. My Grandma Ruth would pull this together whenever we wanted something bright and cozy but she didn’t have the time or energy for a full-on layer cake. It bakes up with a golden, craggy top and glossy lemon peeking through, and in my family it always disappeared before it even cooled. It’s perfect for busy weeknights, last-minute guests, or when you just need something sunny and nostalgic without dirtying every dish in the kitchen.
Serve this lemon dump cake warm, scooped straight from the white casserole dish while the top is still crisp and the lemon filling is soft and jammy. A scoop of vanilla ice cream or a spoonful of whipped cream melts into all the crags and makes it feel extra cozy. For something a little lighter, pair it with fresh berries or sliced strawberries on the side. It’s great with coffee after dinner, or with hot tea on a gray afternoon when you need something bright and comforting but don’t want to fuss with a from-scratch dessert.
Grandma Ruth’s Lemon Dump Cake
Ingredients
2 cans (21 ounces each) lemon pie filling
1 box (15.25 ounces) yellow cake mix (dry, unprepared)
1/2 cup (1 stick) unsalted butter, melted
2 tablespoons unsalted butter, cut into small cubes (optional, for extra golden spots)
Nonstick cooking spray or butter, for greasing the baking dish
Directions
Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch white ceramic baking dish with nonstick spray or a little butter so the edges don’t stick.
Spoon the lemon pie filling into the prepared baking dish and spread it into an even layer, making sure it reaches all the corners. This is your bright, cozy base.
Sprinkle the dry yellow cake mix evenly over the lemon pie filling. Try to cover the lemon completely with a light, even blanket of cake mix so you don’t end up with dry pockets.
Drizzle the melted butter slowly and evenly over the entire surface of the dry cake mix. Aim to moisten as much of the cake mix as you can; the butter is what gives you that golden, craggy topping.
If using, scatter the small butter cubes over any spots that still look a little dry. These little pockets of extra butter help create those deeply golden, slightly crunchy patches on top.
Do not stir. Place the baking dish on the center rack of the oven and bake for 35–45 minutes, or until the top is mostly golden brown with some deeper brown edges, and the lemon filling is bubbling up around the sides and through a few cracks on top.
Remove the dish from the oven and let the cake cool on a wire rack for at least 15–20 minutes. It will still be warm and a little gooey, but this short rest helps it set just enough to scoop. In my house, it usually started disappearing before it was fully cooled.
Serve warm, scooped straight from the baking dish. Store any leftovers covered in the refrigerator for up to 3 days; rewarm individual portions in the microwave for 20–30 seconds to bring back that just-baked coziness.
Variations & Tips
To make this feel a little more special without adding much work, you can sprinkle 1/2 to 1 cup of shredded sweetened coconut or sliced almonds over the dry cake mix before adding the butter for a toasty, bakery-style top. If you like extra tart lemon, stir 1–2 tablespoons of fresh lemon juice and a bit of lemon zest into the pie filling before spreading it in the dish. For a slightly lighter version, you can use 6 tablespoons of butter instead of a full stick and a half, or swap half the butter for 1/4 cup of neutral oil; the top will be a bit less rich but still golden. A gluten-free yellow cake mix works well here if you need to avoid gluten—just keep an eye on the baking time, as some gluten-free mixes brown a little faster. Around the holidays, you can add 1 teaspoon of vanilla extract to the pie filling and a light dusting of powdered sugar over the cooled cake for a cozy, almost cobbler-like dessert. And if you’re cooking for a smaller group, bake half the recipe in an 8×8-inch dish; start checking for doneness around 25–30 minutes.
