Preheat oven to 350°F. Grease a 9×13-inch baking dish.

In a large bowl, mix cake mix, eggs, oil, and crushed pineapple with juice until combined.

Pour batter into the prepared baking dish and bake for 30–35 minutes until a toothpick comes out clean.

While the cake is baking, combine sugar, butter, and evaporated milk in a saucepan. Bring to a boil and cook for 2–3 minutes.

Once cake is out of the oven, poke holes all over with a fork.

Pour warm topping over the hot cake and spread evenly.

Sprinkle coconut on top if using.

Let cool before serving.