Preheat the oven to 180°C (356°F).
Add eggs and erythritol to a bowl and whisk together.
Sift in almond flour and baking powder, then mix well.
Add milk and vanilla extract, and mix until well combined.
Pour the batter into a cake pan and smooth the top.
Bake in the preheated oven for 25–30 minutes.
Let it cool completely before removing from the pan.