Preheat the oven to 170°C.
Add eggs, erythritol, and vanilla extract to a bowl and mix well.
Sift in almond flour, cocoa powder, baking powder, and salt, then combine.
Melt milk and unsalted butter, then add to the batter and mix.
Add vinegar and red colored food coloring to adjust the color.
Pour the batter into the mold and bake in the oven for 25 minutes.
Cool, then decorate with protein cream made by mixing cream cheese, Greek yogurt, and erythritol.