Whisk together the egg, cocoa powder, sweetener, chocolate chops, and espresso powder. Stir in the mozzarella.
Add half of the batter to the waffle maker and cook for 3 minutes. Repeat with remaining batter.
To make the peanut butter filling:
Add all of the ingredients to small bowl and stir together with a fork until smooth and creamy.
To assemble:
Let waffles cool before spreading with the peanut butter and closing to form a sandwich.
Notes
Please note that I've deducted sugar alcohols from this recipe as erythritol generally has no effect on blood sugar. If you count sugar alcohols in your carb count, you'll want to calculate this yourself.These are thick and rich. We count 1/4 of the sandwich as a serving.