Grandma Jo swore you could bring this to any potluck and come home with an empty dish.

This key lime dump cake is the sort of dish my Grandma Jo would carry into a church basement or county fair pavilion, set down on the dessert table, and like clockwork, she’d come home with an empty white baking dish and maybe a few crumbs. It’s a true Midwestern potluck classic in spirit: three pantry-friendly ingredients, no fussing with mixers, and a sunny, citrusy flavor that feels like a little vacation in the middle of farm country. The recipe leans on canned key lime pie filling, a box of yellow cake mix, and melted butter to create a golden, buttery crumb top with gooey, tart-sweet pockets underneath. It’s the kind of everyday miracle dessert you can throw together in minutes when the neighbor calls to say there’s a gathering tonight and you promised to bring something “Grandma-good.”

Serve this key lime dump cake warm, scooped straight from the white baking dish, with a generous spoonful of softly whipped cream or a scoop of vanilla ice cream to mellow the tartness. A little grated lime zest on top looks pretty if you’ve got a fresh lime handy, but it’s not required. It travels well, so bake it in a sturdy ceramic or glass dish and bring it right to the potluck on a kitchen towel-lined sheet pan. Coffee, iced tea, or a cold glass of milk all pair nicely with the bright, buttery flavors, and it’s especially welcome after a spread of casseroles, ham, or grilled brats.

Servings: 10-12

2 cans (20–22 oz each) key lime pie filling

Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch white ceramic baking dish with nonstick spray or a thin coat of butter.

Open the cans of key lime pie filling and spoon them into the prepared baking dish. Spread the filling into an even layer, making sure it reaches all the corners. If using lime zest, you can stir half of it into the filling right in the dish.

Sprinkle the dry yellow cake mix evenly over the key lime pie filling. Use your hands or a spoon to gently level it out so there are no big mounds of dry mix. Do not stir; the layers should stay separate.

If using shredded coconut, sprinkle it evenly over the top of the dry cake mix for a little extra texture and flavor.

Slowly drizzle the melted butter over the entire surface of the cake mix, trying to cover as much of the dry mix as you can. A few small dry spots are fine; they’ll pick up moisture as the cake bakes.

Place the baking dish on the middle rack of the preheated oven. Bake for 35–45 minutes, or until the top is mostly golden brown, the edges are bubbly and slightly gooey, and the center looks set with a few moist spots.

Remove the dish from the oven and let the dump cake cool on a wire rack or on your speckled countertop for at least 15–20 minutes. This rest time helps the filling thicken slightly while keeping the edges gooey.