Here is what I did:
Line a rimmed pan with foil or wax paper. I used a cookie sheet. You may need to experiment with size and it depends on how thick you want your bark to be.
3/4 cup coconut oil, melted
3/4 cup cocoa
Mix well. Add sweetener of your choice to taste. I used:
2 Tbsp granulated erythritol (any powdered sugar substitute will do)
10 drops liquid stevia
I don't like it at all sweet, so feel free to add as much as you like. Too much liquid may affect the final texture.
Mix well. Pour half out onto your prepared pan. While it's still liquid, add nuts or other fillings of your choice. Pour the remaining chocolate over fillings so they're coated.
Filling Variations:
Any nuts or seeds of your choice
Dried fruits
Cocoa nibs
Coconut
I used about a cup of pecan halves and a small handful of cocoa nibs.
I finished with a small sprinkle of the granulated erythritol, just because I like the little added crunch! It's exactly like regular sugar in that regard.
Place pan in refrigerator or freezer until firm. Break or cut into pieces and store in refrigerator or freezer.
A little funny story - while making this, I decided to mix the pecans in so they would be well coated. I store my nuts in the freezer, and had gotten them out to come to room temperature as I was mixing the rest. But I forgot to check first! The instant I poured them in, the coconut oil hardened. I could have ended up with some awesome pecan clusters. I ended up sticking it in the microwave for 20 seconds to soften it back up enough to spread it properly. Lesson learned!