Preheat the oven to 180°C (356°F).
Add the eggs and zero-calorie sweetener to a bowl and whisk together.
Sift in cocoa powder, almond flour, baking powder, and salt.
Add unsalted butter and unsweetened almond milk, mixing until the batter is well combined.
Pour the batter into a pound cake pan.
Bake in the preheated oven at 180°C (356°F) for 30 minutes.
Place on a cooling rack and let it cool completely.