Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan with butter to prevent sticking.

In a large mixing bowl, combine flour, sugar, baking soda, eggs, vanilla extract, and crushed pineapple (with juice). Mix thoroughly until smooth.

Pour the batter into the prepared baking pan and spread evenly. Bake in the preheated oven for 40-45 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.

While the cake bakes, prepare the topping. In a medium-sized saucepan, combine butter, sugar and evaporated milk. Stir constantly over medium heat until the mixture comes to a boil.

Once the mixture boils, stir in chopped pecans and sweetened coconut flakes. Continue cooking and stirring for 5 minutes until thickened.

Remove the cake from the oven and immediately poke holes using the handle of a wooden spoon. Pour the warm topping evenly over the cake, ensuring it soaks into the holes.

Allow the cake to cool slightly for 10-15 minutes. Serve warm or at room temperature, ensuring each slice has a generous portion of the pecan-coconut topping.