Preheat oven to 350°F / 180°C.

Melt 1 stick of butter in a 13×9 inch baking pan in the oven for about 5 minutes.

When butter has melted, remove pan from the oven.

Stir pineapple juice then pineapple chunks into the pan.

Spoon cake mix over all pineapple chunks covering completely.

Sprinkle coconut on top of cake mix until completely covered.

Cut remaining stick of butter into small cubes and top over coconut.

Bake for 45-60 minutes rotating cake 90° every 15 minutes for even browning of coconut.