Just made this tonight and it turned out great! Thought it was a tad sugary, but it might have been because of my mix of brown, white and coconut sugar since I didn't have anything else. Baked in the round lid of a pyrex pan (18 cm across the bottom, 20 cm on the top) for 28 min and the cake was perfect; not dry and with runny chocolate inside. Used cashew nuts mixed in the dough and slightly less cocoa powder, and a bit more chocolate nibs. One of the easiest recipes of brownie cakes I have tried!
This was very easy. I made this last night for a small meeting and it was a hit. I chopped up all 4 ounces of a Ghirardelli 60% Cacao Bittersweet Baking Bar for the chocolate, used untoasted walnuts and followed the instructions. My only issue was that I checked it at 20 minutes but the pick came out looking very wet and I put it back in for another 5 minutes. The pick came out gooey but I may have been hitting chunks of chocolate. I put it in again for another 5 minutes and might have dried it out too much. Next time I'll do like what was suggested below and just go for 20 minutes and try pecans.
I've made this as is, I've left out the cocoa powder, I've made it without cocoa powder and replaced the chocolate chips with raisins, I've used almonds or pecans in place of walnuts... a great, super-easy recipe.
God... this recipe is SO GOOD! You MUST make it. And yes... vanilla ice cream on the side or on top. It's PERFECTION!
These were very good & easy to make. The cinnamon is a nice touch and use pecans if you have them. Don't overbake - I baked for 20 minutes and they were moist and chewy. Nice served with vanilla ice cream.