Pineapple Tres Leches Cake
Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish. Prepare cake mix according to box instructions, substituting water with reserved pineapple juice. Stir in drained crushed pineapple. Bake as directed and cool completely. In a bowl, mix whole milk, sweetened condensed milk, evaporated milk, and 1/2 cup pineapple juice. Poke holes in the cooled cake with a fork and slowly pour the milk mixture over it. Chill for 2–4 hours. Spread whipped topping evenly, sprinkle with coconut, and garnish with pineapple chunks.