1Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking dish.
2Mix flour, 2 cups white sugar, pineapple, eggs, baking soda, and salt together in a bowl until evenly combined; pour into prepared baking dish.
3Bake in the preheated oven until a toothpick inserted in the center of the cake comes out clean, about 35 minutes.
4Combine 1 cup sugar, evaporated milk, and butter together in a saucepan; bring to a boil. Boil mixture for 1 minute; stir in coconut. Pour mixture evenly over hot cake.