Nutcakes...good eye! I am so glad you linked this recipe, I lost my printed copy and I've been searching for it for over a week around the house and online. Stupid me forgot to save the link to favorites and I just didn't have have the time to search through the hundreds of googled sites with a similarly named recipes. I've tried a couple of other recipes and none were as good as this one. Thank YOU!

I just had chocolate pudding cake at a restaurant and have been seeking a recipe, so thanks for link, nutcakes! Another one I came across is the Cook's Illustrated version: http://www.tastebook.com/recipes/775593-Easiest-Hot-Fudge-Pudding-Cake

oh, nutcakes, that recipe looks great! I love the recipes on that site by the way. it is a shame he doesn't post anymore!

Tweaking a recipe isn't the same as changing an entire flavor profile. There are too many things you'd have to do to change this recipe from lemon to chocolate. While some experiments in the kitchen are fine and can often lead to something great, most baking involves way too much chemistry to be really successful if substitutions are made. In this case, I'd let someone else do the science for me--do what nutcakes says and find a recipe that someone else has tested.

Look for a recipe for chocolate molten lava cake, which, like the lemon recipe, uses separated eggs as a leavener (baking powder or baking soda) to lift and lighten the cake.

I love the lemon pudding cakes, I have not tried the chocolate, but why not use a tested recipe? Google chocolate pudding cakes and pick one This one looks good (copies from Martha)
http://sundaynitedinner.com/chocolate-pudding-cake/