In a saucepan over medium/high heat- heat the pineapple juice, lemon juice, and sugar. Stir so everything is dissolved
Add Cornstarch - continue to stir until very thick (like a paste) Turn the heat up, if it's not thickening.
Temper the eggs - Have the 2 yolks mixed in a bowl, next to you, and take a spoon full of heated mixture.
Whip the heated mixture into the eggs
Add the egg mixture to the saucepan, and continue to whip while the egg is cooking into the mixture. (Only takes a minute)
Remove from heat
Let cool for about 5 minutes
Spread over the second layer (this is a thin layer)- place back in the fridge