Frog Eye Salad

In a medium saucepan, combine 1 3/4 cup of the reserved pineapple juice and the granulated sugar. Whisk over medium heat until dissolved.
Add beaten eggs and flour. Heat mixture to 170°F, whisking constantly. Mixture will thicken to a custard consistency after 10-20 minutes. Remove from heat and let cool completely.
Once cool, add to bowl with fruit. Add marshmallows and coconut and stir to combine. Cover and chill at least 6 hours and preferably overnight.
When ready to serve, stir in the cool whip. Top with additional coconut and marshmallows if desired. Enjoy!