Begin by carefully separating the egg yolks from the egg whites. Be cautious not to let any yolk mix with the egg whites; this will prevent them from beating into stiff peaks.

Place the egg whites in a bowl of an electric mixer and beat until stiff peaks form. Once ready, transfer the whipped egg whites to another bowl.

In the same mixer bowl, add the egg yolks along with the monkfruit sweetener and optional vanilla extract. Cream the mixture until it becomes light and fluffy.

Gently fold in the Greek yogurt until well combined with the egg mix.

Sift the cornstarch into the yogurt and egg mixture, and mix until all the ingredients are combined.

Carefully fold the whipped egg whites back into the yogurt egg batter, maintaining an airy texture.

Line a 7×11 inch baking dish with parchment paper and pour the batter into it.

Place the baking dish on a larger baking sheet. Pour boiling water into the larger baking sheet, just enough to submerge the smaller baking dish about 1/4 to 1/3 of the way.

Preheat your oven to 330°F (160°C) and bake for 45 minutes. After that, raise the temperature to 350°F (180°C) and bake for an additional 15 minutes.

Once finished, turn off the oven and crack the door open, allowing the cake to cool for about 1 to 2 hours.

Slice the cake into squares and place them on a decorative plate.

Consider dusting the top with a light sprinkle of monkfruit sweetener for added sweetness and a touch of elegance.

Pair it with fresh berries or a dollop of whipped cream for a delicious contrast in flavors.

Enjoy it as a light dessert after dinner or as a midday snack alongside a cup of tea or coffee.