Preheat oven to 350°F (175°C). Grease a 9×13 inch baking dish.
Spread crushed pineapple (with juice) evenly in the bottom of the dish.
Layer sliced bananas over the pineapple.
Add sliced strawberries evenly on top.
Sprinkle chocolate chips and nuts over the fruit layers.
Evenly sprinkle the dry cake mix over everything (do not mix).
Drizzle melted butter evenly over the cake mix, covering as much surface as possible.
Bake uncovered for 45–50 minutes, until golden brown and bubbly.
Let cool slightly before serving. Top with whipped cream or ice cream if desired.