Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish.
In a large bowl, mix the crushed pineapple (juice and all), granulated sugar, brown sugar, and eggs until smooth.
Add the flour, baking soda, and salt. Stir until just combined—don’t overmix it.
Pour the batter into your prepared dish and bake for about 35-40 minutes, until golden and a toothpick comes out clean.
While the cake bakes, melt the butter in a saucepan over medium heat. Stir in the evaporated milk, coconut, pecans, and vanilla.
Once the cake is out of the oven, immediately pour the topping over the hot cake.
Let it cool slightly, then serve warm or at room temperature—whatever your mood calls for.