Preheat and prep: Heat your oven to 350°F (175°C).
Lightly grease a 9x13-inch baking dish with nonstick spray or butter.
Add the fruit base: Pour the entire can of crushed pineapple with its juice into the dish. Add the drained fruit cocktail. Spread into an even layer so the fruit covers the bottom.
Season it: Sprinkle the cinnamon and a small pinch of salt over the fruit.
This helps round out the sweetness and adds warmth.
Add the cake mix: Evenly sprinkle the dry cake mix over the fruit. Don’t stir. Aim for a smooth, thin blanket of mix without big mounds.
Butter it up: Drizzle the melted butter evenly across the surface.
Try to cover as much of the dry mix as possible. If there are a few dry patches, that’s okay.
Top with crunch (optional): Sprinkle coconut and/or pecans over the top for extra texture and a toasty finish.
Bake: Place in the center of the oven and bake for 40–50 minutes, until the top is golden brown and the fruit is bubbling around the edges. The center should look set, not powdery.
Rest and serve: Let the cake cool for at least 15 minutes so the juices thicken.
Serve warm by the scoop. It’s excellent with vanilla ice cream or whipped cream.