A castella made with alternative sweeteners.
Separate the egg whites and yolks.
Add erythritol and vanilla extract to the yolks and mix well.
Whip the egg whites until stiff peaks form to make meringue.
Add low-carb flour to the yolk mixture and combine.
Gently fold the meringue into the batter in 2–3 additions.
Pour the batter into the mold and smooth the top.
Bake in a preheated oven at 170°C (338°F) for 30 minutes.