You have gotten a lot of advice - some of which is in line with the way I think and some of which is not. You obviously have to decide what you are comfortable with, I too believe it's not right to "sleep train" a baby to accept that he/she is abandoned so that they fall back to sleep all stressed out. I believe in helping babies learn to fall asleep independently but it sounds like your baby knows how to put himself to sleep so that's not the issue. Especially since all his other sleeping is fine, he seems to know how to sleep so you don't need to teach him. It sounds like he is simply hungry. I agree the chocolate cake comparison is completely irrelevant. His primary source of nutrition at this point is STILL breast milk. I would definitely bolster his food intake during the day if you can.
One suggestion I didn't read in the other posts, and that I did for a LONG time - until 9 or 10 months I think, maybe more. I did what was called a "dreamfeed" recommended by the Baby Whisperer (Tracy Hogg). She believes you should never break a baby's trust by making him cry it out but that you always need to be responsive and sooth and encourage self soothing.
ANyway, the "dreamfeed" is when you go back in and feed the baby one last time before you go to bed. You don't even wake the baby up, just pick him up gently, latch him on and let him nurse - the whole time he stays totally asleep. Now maybe you go to bed at 9:30 and that's what you are doing. If not, I'd go back in and feed him right before you go to bed. I used to go to bed around 11:30 when my little one was that age so I would feed her around 11:15 or 11 and she'd then make it through the night til around 6 or 7. You can give it a try, worked well for me though it took a few nights for ME to get it right - i was at first so nervous about waking her up but she really got it. DOn't change him or anything - just nurse and back in the crib, no burping even.
For me, I enjoyed the nursing time, and wish I would have cherished it even more as she refused to nurse during the day at about 9 months, then gave up her evening feed about a month later and stopped her first morning feed at around 12 months. I was devastated and still miss it as I am pumping now to make sure she still gets a little of that precious human milk even though she's over 2. So you never know when he is just going to call it quits - enjoy it while he does.
Good luck. Your baby sound PERFECTLY fine. He's simply a baby, even if he is big.