Combine Greek yogurt and low-fat cream cheese in a bowl and mix well.
Add erythritol to adjust sweetness.
Prepare regular coffee, cool it, then soak whole wheat bread or oatmeal sheets in the coffee instead of sponge cake.
Layer the soaked bread first in a glass cup, then add the cream on top.
Repeat for multiple layers.
Sift unsweetened cocoa powder over the top.
Refrigerate for at least 1 hour before serving.