Preheat the oven to 350°F (175°C) and grease a 9x13-inch baking dish.
In a large bowl, mix sugar, flour, eggs, baking soda, salt, and crushed pineapple with its juice until just combined.
Gently fold in pecans and shredded coconut. Pour batter into the prepared baking dish, spreading evenly.
Bake for 35–40 minutes, or until a toothpick inserted in the center comes out clean.
While the cake bakes, prepare the glaze: In a saucepan over medium heat, combine butter, sugar, and evaporated milk. Bring to a gentle boil, stirring constantly, then reduce heat and simmer for 5 minutes.
Remove from heat and stir in vanilla, pecans, and coconut.
Pour the warm glaze over the hot cake, spreading it evenly so every bite is coated.
Allow the cake to cool slightly before slicing and serving. Serve warm or at room temperature.
Notes
This cake is even better the next day as the flavors meld together. Store covered at room temperature or refrigerate for longer freshness.