Beat egg whites on high until foamy
Add cornstarch and salt to egg whites
Continue beating until stiff peaks form
Add vanilla and sweetener for a few seconds, being careful not to deflate
Spray parchment paper with cooking oil and spread meringue mixture on a baking pan
Bake at 400F for 8-10 minutes until lightly golden brown
Turn off oven and leave meringue inside with door open for 2 minutes
Set aside some of the meringue for topping
Mix greek yogurt, cream cheese, lemon zest, lemon juice, sweetener, and salt
Spread filling mixture on the meringue base
Roll up the meringue and serve
