01 - Preheat oven to 350°F. Thoroughly grease a 9x13-inch baking pan with butter or cooking spray.
02 - In a large mixing bowl, sift together flour, sugar, baking soda, and salt. Whisk until uniformly blended.
03 - Add beaten eggs and vanilla to the flour mixture. Pour in the entire can of crushed pineapple including all juice. Stir gently until just combined—batter will appear thin and slightly lumpy.
04 - Fold in chopped pecans and shredded coconut using a spatula, distributing evenly throughout the batter.
05 - Pour batter into the prepared pan, spreading level with an offset spatula. Bake for 35-40 minutes until golden brown and a toothpick inserted in the center emerges clean.
06 - While cake bakes, combine sugar, butter, and evaporated milk in a medium saucepan over medium heat. Bring to a gentle boil while stirring constantly, then cook 3-4 minutes until slightly thickened. Remove from heat and stir in vanilla.
07 - Immediately upon removing cake from oven, pierce the surface every inch with a fork or skewer. Pour hot sauce evenly over the hot cake. Cool completely in pan before cutting into 12 squares.