Heat the oven to 350°F and spread the pineapple with all its juice in a 9-by-13-inch dish.

Cover the fruit with an even layer of dry cake mix.

Scatter coconut over the mix and drizzle melted butter slowly across the full surface.

Bake for 45 to 50 minutes until the coconut is toasted, the crust is browned and pineapple bubbles at the edges.

Rest 25 minutes before serving.