I'm going to have to make this again but I do believe adding cream will make it more of a milk chocolate and get rid of some of the bitterness. You can also replace some of the baking chocolate with ChocZero milk chocolate baking chips.

Has an ingredient been left out of recipe? Cream is mentioned in a comment response above, but no cream is listed in ingredients list.

I’ll try this again, but I’ll use more sweetener. I love the texture!

It sounds like a temperature issue. If you let it cool a bit, it should have blended in.

I don’t know what I could have done wrong as I followed the directions completely and I am a decent baker but the mixture ended up separating for me once I slowly added the eggs in. It was a complete waste. I decided to put it in the oven just to see what would happen knowing it wouldn’t be right and it was just a clumpy, oily mess. I used the stevia powdered baking sweetener, but didn’t deviate in any other way. I’ve never seen anything like it.

It's the first ingredient listed.

The cake can probably be frozen safely for at least 3 months, but I haven't tried it myself. In the fridge it should last a week or two. I recommend keeping it in the refrigerator as there isn't any sugar in it.

The low carb sweetener is a one-for-one sugar sub so the amount should be about the same.

You can add in more cream if it's too thick and more sweetener to offset the bitter taste of the cocoa. The cream also makes it more of a "milk" chocolate which lessens the bitterness of the cocoa.