Bring a large pot of salted water to a boil.
Add the acini di pepe pasta.
Cook for 8 to 10 minutes, stirring occasionally, until the pasta is al dente.
Drain the pasta in a colander.
Set the pasta aside and allow it to cool.
In a medium saucepan over medium heat, combine the pineapple juice, granulated sugar, flour, beaten egg, beaten egg yolk, and salt.
Whisk continuously until the mixture comes to a boil.
Continue whisking for 1 to 2 minutes, or until the custard thickens.
Transfer the thickened custard to a glass bowl.
Allow the custard to cool slightly.
Stir in the lemon juice.
Once the custard and pasta have cooled, pour the custard over the pasta.
Stir until the pasta is evenly coated.
Cover and refrigerate for at least 2 hours, or until well chilled.
Add the heavy whipping cream to a large mixing bowl.
Using an electric mixer, beat until stiff peaks form.
Add the marshmallow creme.
Beat on medium speed for approximately 30 seconds, or until combined.
In a large serving bowl, combine the chilled pasta mixture, whipped cream mixture, pineapple tidbits, crushed pineapple, mandarin oranges, miniature marshmallows, and shredded coconut.
Fold gently until all ingredients are evenly incorporated.
Garnish with additional whipped cream, mandarin orange slices, and maraschino cherries, if desired.
Serve chilled.