Last week I was looking for a recipe for something chocolatey using buckwheat and my daughter came up with Nigella's gluten free Triple Chocolate Buckwheat Cookies. Knowing that Nigella's recipes are usually luscious I added the ingredients to my click and collect order: unfortunately through the vagueries of substitution we didn't end up with the quite the right ingredients, so she used what we had and the cookies were still delicious: extremely chocolatey and soft in the middle, although more cakey than chewy. I think we must have more generous ideas of a rounded teaspoon of mixture because we only ended up with a baker's dozen rather than the 20 she suggests.
I am giving the ingredients for the cookies as we made them; if you want Nigella's original version you will find it in her book "Simply Nigella"