Preheat your oven to 350°F. In a large mixing bowl, combine the yellow cake mix, eggs, oil, and pineapple juice. Stir gently until the batter becomes smooth and evenly mixed, taking care not to overmix. Transfer the batter to a greased 9x13 inch baking dish and bake for 25-30 minutes, checking for doneness with a toothpick inserted into the center—it should come out clean when the cake is ready.

Take the cake out of the oven and allow it to rest in the pan for 10 minutes so it sets slightly while still warm. Use a fork or wooden skewer to poke holes throughout the entire cake surface, spacing them approximately 1 inch apart. Make sure you create plenty of holes so the gelatin can soak in properly and form flavorful pockets.

In a medium bowl, combine the pineapple gelatin powder with the boiling water. Stir steadily for about 2 minutes until the gelatin dissolves completely with no visible granules. Allow the mixture to cool for 3-5 minutes until it's warm but not too hot. Carefully pour the gelatin over the cake surface, ensuring it seeps into all the holes you created. Pour gradually if needed to prevent pooling on top.

Transfer the cake to the refrigerator and chill for at least 45 minutes until the gelatin sets completely and doesn't jiggle when you gently shake the pan. This step is essential for achieving proper texture, so don't rush it.

In a large bowl, combine the whipped topping, vanilla extract, and drained pineapple chunks. Use a folding motion rather than stirring to keep the mixture light and airy, blending until everything is evenly distributed.

Spread the pineapple-whipped topping mixture over the chilled cake in an even layer, starting from the center and working outward. Scatter the toasted coconut generously across the top, then arrange the maraschino cherries in an attractive pattern. Place the finished cake back in the refrigerator for 1-2 hours before serving to allow the layers to set and meld together for the ideal chilled consistency.