1. Preheat oven to 350°F (175°C).
2. In a large bowl, combine the dry angel food cake mix and instant vanilla pudding mix.
3. Add the entire undrained 20 oz can of crushed pineapple and gently stir until the mixture thickens and is well combined, taking care not to overmix to maintain a light, airy texture.
4. Spread the batter evenly in an ungreased 9×13 inch baking pan.
5. Bake for 25-30 minutes, or until the top is golden brown and springs back when lightly touched.
6. Let the cake cool completely in the pan to ensure the whipped topping doesn’t melt when applied.
7. Spread the thawed whipped topping evenly over the cooled cake.
8. Drain and lightly pat dry the second 8 oz can of crushed pineapple, then spread it evenly over the whipped topping layer.
9. Garnish with toasted shredded coconut and maraschino cherries if desired.
10. Refrigerate the cake for at least 2 hours before serving to allow flavors to meld and the texture to set. Serve slightly chilled by removing from the refrigerator about 15 minutes before slicing.