Separate yolks from egg whites making sure not to leak any yolk into egg whites as they won't beat to stiff peaks.
Pour egg whites into a bowl of electric mixer and beat until stiff peaks form.
Add monkfruit sweetener to egg yolks along with vanilla extract if desired; cream until light and fluffy.
Incorporate Greek yogurt into creamed mixture after fluffing up yolks well.
Sift cornstarch over mixture then gently fold all components together carefully.
Fold previously beaten egg whites gradually into batter without deflating them too much.
Prepare baking pan using parchment paper before pouring finished batter inside evenly across surface area.
Set up double boiler by placing filled pan atop larger one filled partly with boiling water—this ensures moisture during baking!
Bake in preheated oven at designated temperatures based on steps provided earlier; check doneness visually after suggested time intervals have passed accordingly!
Allow cooling period after finishing baking process before serving warm or chilled based on preference!